Tag Archives: touch

‘Pirate’ Kodi Addon Devs & Distributors Told to Cease-and-Desist

Post Syndicated from Andy original https://torrentfreak.com/pirate-kodi-addon-devs-distributors-told-to-cease-and-desist-180214/

Last November, following a year of upheaval for third-party addon creators and distributors, yet more turmoil hit the community in the form of threats from the world’s most powerful anti-piracy coalition – the Alliance for Creativity and Entertainment (ACE).

Comprised of 30 companies including the studios of the MPAA, Amazon, Netflix, CBS, HBO, BBC, Sky, Bell Canada, CBS, Hulu, Lionsgate, Foxtel, Village Roadshow, and many more, ACE warned several developers to shut down – or else.

The letter: shut down – or else

Now it appears that ACE is on the warpath again, this time targeting a broader range of individuals involved in the Kodi addon scene, from developers and distributors to those involved in the production of how-to videos on YouTube.

The first report of action came from TVAddons, who noted that the lead developer at the Noobs and Nerds repository had been targeted with a cease-and-desist notice, adding that people from the site had been “visited at their homes.”

As seen in the image below, the Noobs and Nerds website is currently down. The site’s Twitter account has also been disabled.

Noobs and Nerds – gone

While TVAddons couldn’t precisely confirm the source of the threat, information gathered from individuals involved in the addon scene all point to the involvement of ACE.

In particular, a man known online as Teverz, who develops his own builds, runs a repo, and creates Kodi-themed YouTube videos, confirmed that ACE had been in touch.

An apparently unconcerned Teverz….

“I am not a dev so they really don’t scare me lmao,” he added.

Teverz claims to be from Canada and it appears that others in the country are also facing cease and desist notices. An individual known as Doggmatic, who also identifies as Canadian and has Kodi builds under his belt, says he too was targeted.

Another target in Canada

Doggmatic, who appears to be part of the Illuminati repo, says he had someone call the people who sent the cease-and-desist but like Teverz, he doesn’t seem overly concerned, at least for now.

“I have a legal representative calling them. The letters they sent aren’t legal documents. No lawyer signed them and no law firm mentioned,” Doggmatic said.

But the threats don’t stop there. Blamo, the developer of the Neptune Rising addon accessible from the Blamo repo, also claims to have been threatened.

SpinzTV, who offers unofficial Kodi builds and an associated repository, is also under the spotlight. Unlike his Canadian counterparts, he has already thrown in the towel, according to a short announcement on Twitter.

For SpinzTV it’s all over…

TorrentFreak contacted the Alliance for Creativity and Entertainment, asking them if they could confirm the actions and provide any additional details. At the time of publication they had no information for us but we’ll update if and when that comes in.

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

Integration With Zapier

Post Syndicated from Bozho original https://techblog.bozho.net/integration-with-zapier/

Integration is boring. And also inevitable. But I won’t be writing about enterprise integration patterns. Instead, I’ll explain how to create an app for integration with Zapier.

What is Zapier? It is a service that allows you tо connect two (or more) otherwise unconnected services via their APIs (or protocols). You can do stuff like “Create a Trello task from an Evernote note”, “publish new RSS items to Facebook”, “append new emails to a spreadsheet”, “post approaching calendar meeting to Slack”, “Save big email attachments to Dropbox”, “tweet all instagrams above a certain likes threshold”, and so on. In fact, it looks to cover mostly the same usecases as another famous service that I really like – IFTTT (if this then that), with my favourite use-case “Get a notification when the international space station passes over your house”. And all of those interactions can be configured via a UI.

Now that’s good for end users but what does it have to do with software development and integration? Zapier (unlike IFTTT, unfortunately), allows custom 3rd party services to be included. So if you have a service of your own, you can create an “app” and allow users to integrate your service with all the other 3rd party services. IFTTT offers a way to invoke web endpoints (including RESTful services), but it doesn’t allow setting headers, so that makes it quite limited for actual APIs.

In this post I’ll briefly explain how to write a custom Zapier app and then will discuss where services like Zapier stand from an architecture perspective.

The thing that I needed it for – to be able to integrate LogSentinel with any of the third parties available through Zapier, i.e. to store audit logs for events that happen in all those 3rd party systems. So how do I do that? There’s a tutorial that makes it look simple. And it is, with a few catches.

First, there are two tutorials – one in GitHub and one on Zapier’s website. And they differ slightly, which becomes tricky in some cases.

I initially followed the GitHub tutorial and had my build fail. It claimed the zapier platform dependency is missing. After I compared it with the example apps, I found out there’s a caret in front of the zapier platform dependency. Removing it just yielded another error – that my node version should be exactly 6.10.2. Why?

The Zapier CLI requires you have exactly version 6.10.2 installed. You’ll see errors and will be unable to proceed otherwise.

It appears that they are using AWS Lambda which is stuck on Node 6.10.2 (actually – it’s 6.10.3 when you check). The current major release is 8, so minus points for choosing … javascript for a command-line tool and for building sandboxed apps. Maybe other decisions had their downsides as well, I won’t be speculating. Maybe it’s just my dislike for dynamic languages.

So, after you make sure you have the correct old version on node, you call zapier init and make sure there are no carets, npm install and then zapier test. So far so good, you have a dummy app. Now how do you make a RESTful call to your service?

Zapier splits the programmable entities in two – “triggers” and “creates”. A trigger is the event that triggers the whole app, an a “create” is what happens as a result. In my case, my app doesn’t publish any triggers, it only accepts input, so I won’t be mentioning triggers (though they seem easy). You configure all of the elements in index.js (e.g. this one):

const log = require('./creates/log');
....
creates: {
    [log.key]: log,
}

The log.js file itself is the interesting bit – there you specify all the parameters that should be passed to your API call, as well as making the API call itself:

const log = (z, bundle) => {
  const responsePromise = z.request({
    method: 'POST',
    url: `https://api.logsentinel.com/api/log/${bundle.inputData.actorId}/${bundle.inputData.action}`,
    body: bundle.inputData.details,
	headers: {
		'Accept': 'application/json'
	}
  });
  return responsePromise
    .then(response => JSON.parse(response.content));
};

module.exports = {
  key: 'log-entry',
  noun: 'Log entry',

  display: {
    label: 'Log',
    description: 'Log an audit trail entry'
  },

  operation: {
    inputFields: [
      {key: 'actorId', label:'ActorID', required: true},
      {key: 'action', label:'Action', required: true},
      {key: 'details', label:'Details', required: false}
    ],
    perform: log
  }
};

You can pass the input parameters to your API call, and it’s as simple as that. The user can then specify which parameters from the source (“trigger”) should be mapped to each of your parameters. In an example zap, I used an email trigger and passed the sender as actorId, the sibject as “action” and the body of the email as details.

There’s one more thing – authentication. Authentication can be done in many ways. Some services offer OAuth, others – HTTP Basic or other custom forms of authentication. There is a section in the documentation about all the options. In my case it was (almost) an HTTP Basic auth. My initial thought was to just supply the credentials as parameters (which you just hardcode rather than map to trigger parameters). That may work, but it’s not the canonical way. You should configure “authentication”, as it triggers a friendly UI for the user.

You include authentication.js (which has the fields your authentication requires) and then pre-process requests by adding a header (in index.js):

const authentication = require('./authentication');

const includeAuthHeaders = (request, z, bundle) => {
  if (bundle.authData.organizationId) {
	request.headers = request.headers || {};
	request.headers['Application-Id'] = bundle.authData.applicationId
	const basicHash = Buffer(`${bundle.authData.organizationId}:${bundle.authData.apiSecret}`).toString('base64');
	request.headers['Authorization'] = `Basic ${basicHash}`;
  }
  return request;
};

const App = {
  // This is just shorthand to reference the installed dependencies you have. Zapier will
  // need to know these before we can upload
  version: require('./package.json').version,
  platformVersion: require('zapier-platform-core').version,
  authentication: authentication,
  
  // beforeRequest & afterResponse are optional hooks into the provided HTTP client
  beforeRequest: [
	includeAuthHeaders
  ]
...
}

And then you zapier push your app and you can test it. It doesn’t automatically go live, as you have to invite people to try it and use it first, but in many cases that’s sufficient (i.e. using Zapier when doing integration with a particular client)

Can Zapier can be used for any integration problem? Unlikely – it’s pretty limited and simple, but that’s also a strength. You can, in half a day, make your service integrate with thousands of others for the most typical use-cases. And not that although it’s meant for integrating public services rather than for enterprise integration (where you make multiple internal systems talk to each other), as an increasing number of systems rely on 3rd party services, it could find home in an enterprise system, replacing some functions of an ESB.

Effectively, such services (Zapier, IFTTT) are “Simple ESB-as-a-service”. You go to a UI, fill a bunch of fields, and you get systems talking to each other without touching the systems themselves. I’m not a big fan of ESBs, mostly because they become harder to support with time. But minimalist, external ones might be applicable in certain situations. And while such services are primarily aimed at end users, they could be a useful bit in an enterprise architecture that relies on 3rd party services.

Whether it could process the required load, whether an organization is willing to let its data flow through a 3rd party provider (which may store the intermediate parameters), is a question that should be answered in a case by cases basis. I wouldn’t recommend it as a general solution, but it’s certainly an option to consider.

The post Integration With Zapier appeared first on Bozho's tech blog.

The Early Days of Mass Internet Piracy Were Awesome Yet Awful

Post Syndicated from Andy original https://torrentfreak.com/the-early-days-of-mass-internet-piracy-were-awesome-yet-awful-180211/

While Napster certainly put the digital cats among the pigeons in 1999, the organized chaos of mass Internet file-sharing couldn’t be truly appreciated until the advent of decentralized P2P networks a year or so later.

In the blink of an eye, everyone with a “shared folder” client became both a consumer and publisher, sucking in files from strangers and sharing them with like-minded individuals all around the planet. While today’s piracy narrative is all about theft and danger, in the early 2000s the sharing community felt more like distant friends who hadn’t met, quietly trading cards together.

Satisfying to millions, those who really engaged found shared folder sharing a real adrenaline buzz, as English comedian Seann Walsh noted on Conan this week.

“Click. 20th Century Fox comes up. No pixels. No shaky cam. No silhouettes of heads at the bottom of the screen, people coming in five minutes late. None of that,” Walsh said, recalling his experience of downloading X-Men 2 (X2) from LimeWire.

“We thought: ‘We’ve done it!!’ This was incredible! We were going to have to go to the cinema. We weren’t going to have to wait for the film to come out on video. We weren’t going to have to WALK to blockbuster!”

But while the nostalgia has an air of magic about it, Walsh’s take on the piracy experience is bittersweet. While obtaining X2 without having to trudge to a video store was a revelation, there were plenty of drawbacks too.

Downloading the pirate copy took a week, which pre-BitTorrent wasn’t a completely bad result but still a considerable commitment. There were also serious problems with quality control.

“20th Century fades, X Men 2 comes up. We’ve done it! We’re not taking it for granted – we’re actually hugging. Yes! Yes! We’ve done it! This is the future! We look at the screen, Wolverine turns round…,” …..and Walsh launches into a broadside of pseudo-German babble, mimicking the unexpectedly-dubbed superhero.

After a week of downloading and getting a quality picture on launch, that is a punch in the gut, to say the least. Arguably no less than a pirate deserves, some will argue, but a fat lip nonetheless, and one many a pirate has suffered over the years. Nevertheless, as Walsh notes, it’s a pain that kids in 2018 simply cannot comprehend.

“Children today are living the childhood I dreamed of. If they want to hear a song – touch – they stream it. They’ve got it now. Bang. Instantly. They don’t know the pain of LimeWire.

“Start downloading a song, go to school, come back. HOPE that it’d finished! That download bar messing with you. Four minutes left…..nine HOURS and 28 minutes left? Thirty seconds left…..52 hours and 38 minutes left? JUST TELL ME THE TRUTH!!!!!” Walsh pleaded.

While this might sound comical now, this was the reality of people downloading from clients such as LimeWire and Kazaa. While X2 in German would’ve been torture for a non-German speaker, the misery of watching an English language copy of 28 Days Later somehow crammed into a 30Mb file is right up there too.

Mislabeled music with microscopic bitrates? That was pretty much standard.

But against the odds, these frankly second-rate experiences still managed to capture the hearts and minds of the digitally minded. People were prepared to put up with nonsense and regular disappointment in order to consume content in a way fit for the 21st century. Yet somehow the combined might of the entertainment industries couldn’t come up with anything substantially better for a number of years.

Of course, broadband availability and penetration played its part but looking back, something could have been done. Not only didn’t the Internet’s popularity come as a surprise, people’s expectations were dramatically lower than they are today too. In any event, beating the pirates should have been child’s play. After all, it was just regular people sharing files in a Windows folder.

Any fool could do it – and millions did. Surprisingly, they have proven unstoppable.

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

Barbot 4: the bartending Grandfather clock

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/barbot-4/

Meet Barbot 4, the drink-dispensing Grandfather clock who knows when it’s time to party.

Barbot 4. Grandfather Time (first video of cocktail robot)

The first introduction to my latest barbot – this time made inside a grandfather clock. There is another video where I explain a bit about how it works, and am happy to give more explanations. https://youtu.be/hdxV_KKH5MA This can make cocktails with up to 4 spirits, and 4 mixers, and is controlled by voice, keyboard input, or a gui, depending which is easiest.

Barbot 4

Robert Prest’s Barbot 4 is a beverage dispenser loaded into an old Grandfather clock. There’s space in the back for your favourite spirits and mixers, and a Raspberry Pi controls servo motors that release the required measures of your favourite cocktail ingredients, according to preset recipes.

Barbot 4 Raspberry Pi drink-dispensing robot

The clock can hold four mixers and four spirits, and a human supervisor records these using Drinkydoodad, a friendly touchscreen interface. With information about its available ingredients and a library of recipes, Barbot 4 can create your chosen drink. Patrons control the system either with voice commands or with the touchscreen UI.

Barbot 4 Raspberry Pi drink-dispensing robot

Robert has experimented with various components as this project has progressed. He has switched out peristaltic pumps in order to increase the flow of liquid, and adjusted the motors so that they can handle carbonated beverages. In the video, he highlights other quirks he hopes to address, like the fact that drinks tend to splash during pouring.

Barbot 4 Raspberry Pi drink-dispensing robot

As well as a Raspberry Pi, the build uses Arduinos. These control the light show, which can be adjusted according to your party-time lighting preferences.

An explanation of the build accompanies Robert’s second video. We’re hoping he’ll also release more details of Barbot 3, his suitcase-sized, portable Barbot, and of Doom Shot Bot, a bottle topper that pours a shot every time you die in the game DoomZ.

Automated bartending

Barbot 4 isn’t the first cocktail-dispensing Raspberry Pi bartender we’ve seen, though we have to admit that fitting it into a grandfather clock definitely makes it one of the quirkiest.

If you’ve built a similar project using a Raspberry Pi, we’d love to see it. Share your project in the comments, or tell us what drinks you’d ask Barbot to mix if you had your own at home.

The post Barbot 4: the bartending Grandfather clock appeared first on Raspberry Pi.

Udemy Targets ‘Pirate’ Site Giving Away its Paid Courses For Free

Post Syndicated from Andy original https://torrentfreak.com/udemy-targets-pirate-site-giving-away-its-paid-courses-for-free-180129/

While there’s no shortage of people who advocate free sharing of movies and music, passions are often raised when it comes to the availability of educational information.

Significant numbers of people believe that learning should be open to all and that texts and associated materials shouldn’t be locked away by copyright holders trying to monetize knowledge. Of course, people who make a living creating learning materials see the position rather differently.

A clash of these ideals is brewing in the United States where online learning platform Udemy has been trying to have some of its courses taken down from FreeTutorials.us, a site that makes available premium tutorials and other learning materials for free.

Early December 2017, counsel acting for Udemy and a number of its individual and corporate instructors (Maximilian Schwarzmüller, Academind GmbH, Peter Dalmaris, Futureshock Enterprises, Jose Marcial Portilla, and Pierian Data) wrote to FreeTutorials.us with DMCA takedown notice.

“Pursuant to 17 U.S.C. § 512(c)(3)(A) of the Digital Millennium Copyright Act (‘DMCA’), this communication serves as a notice of infringement and request for removal of certain web content available on freetutorials.us,” the letter reads.

“I hereby request that you remove or disable access to the material listed in Exhibit A in as expedient a fashion as possible. This communication does not constitute a waiver of any right to recover damages incurred by virtue of any such unauthorized activities, and such rights as well as claims for other relief are expressly retained.”

A small sample of Exhibit A

On January 10, 2018, the same law firm wrote to Cloudflare, which provides services to FreeTutorials. The DMCA notice asked Cloudflare to disable access to the same set of infringing content listed above.

It seems likely that whatever happened next wasn’t to Udemy’s satisfaction. On January 16, an attorney from the same law firm filed a DMCA subpoena at a district court in California. A DMCA subpoena can enable a copyright holder to obtain the identity of an alleged infringer without having to file a lawsuit and without needing a signature from a judge.

The subpoena was directed at Cloudflare, which provides services to FreeTutorials. The company was ordered to hand over “all identifying information identifying the owner, operator and/or contact person(s) associated with the domain www.freetutorials.us, including but not limited to name(s), address(es), telephone number(s), email address(es), Internet protocol connection records, administrative records and billing records from the time the account was established to the present.”

On January 26, the date by which Cloudflare was ordered to hand over the information, Cloudflare wrote to FreeTutorials with a somewhat late-in-the-day notification.

“We received the attached subpoena regarding freetutorials.us, a domain managed through your Cloudflare account. The subpoena requires us to provide information in our systems related to this website,” the company wrote.

“We have determined that this is a valid subpoena, and we are required to provide the requested information. In accordance with our Privacy Policy, we are informing you before we provide any of the requested subscriber information. We plan to turn over documents in response to the subpoena on January 26th, 2018, unless you intervene in the case.”

With that deadline passing last Friday, it’s safe to say that Cloudflare has complied with the subpoena as the law requires. However, TorrentFreak spoke with FreeTutorials who told us that the company doesn’t hold anything useful on them.

“No, they have nothing,” the team explained.

Noting that they’ll soon dispense with the services of Cloudflare, the team confirmed that they had received emails from Udemy and its instructors but hadn’t done a lot in response.

“How about a ‘NO’? was our answer to all the DMCA takedown requests from Udemy and its Instructors,” they added.

FreeTutorials (FTU) are affiliated with FreeCoursesOnline (FCO) and seem passionate about what they do. In common with others who distribute learning materials online, they express a belief in free education for all, irrespective of financial resources.

“We, FTU and FCO, are a group of seven members assorted as a team from different countries and cities. We are JN, SRZ aka SunRiseZone, Letap, Lihua Google Drive, Kaya, Zinnia, Faiz MeemBazooka,” a spokesperson revealed.

“We’re all members and colleagues and we also have our own daily work and business stuff to do. We have been through that phase of life when we didn’t have enough money to buy books and get tuition or even apply for a good course that we always wanted to have, so FTU & FCO are just our vision to provide Free Education For Everyone.

“We would love to change our priorities towards our current and future projects, only if we manage to get some faithful FTU’ers to join in and help us to grow together and make FTU a place it should be.”

TorrentFreak requested comment from Udemy but at the time of publication, we were yet to hear back. However, we did manage to get in touch with Jonathan Levi, an Udemy instructor who sent this takedown notice to the site in October 2017:

“I’m writing to you on behalf of SuperHuman Enterprises, LLC. You are in violation of our copyright, using our images, and linking to pirated copies of our courses. Remove them IMMEDIATELY or face severe legal action….You have 48 hours to comply,” he wrote, adding:

“And in case you’re going to say I don’t have evidence that I own the files, it’s my fucking face in the videos.”

Levi says that the site had been non-responsive so now things are being taken to the next level.

“They don’t reply to takedowns, so we’ve joined a class action lawsuit against FTU lead by Udemy and a law firm specializing in this type of thing,” Levi concludes.

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

Cloud Babble: The Jargon of Cloud Storage

Post Syndicated from Andy Klein original https://www.backblaze.com/blog/what-is-cloud-computing/

Cloud Babble

One of the things we in the technology business are good at is coming up with names, phrases, euphemisms, and acronyms for the stuff that we create. The Cloud Storage market is no different, and we’d like to help by illuminating some of the cloud storage related terms that you might come across. We know this is just a start, so please feel free to add in your favorites in the comments section below and we’ll update this post accordingly.

Clouds

The cloud is really just a collection of purpose built servers. In a public cloud the servers are shared between multiple unrelated tenants. In a private cloud, the servers are dedicated to a single tenant or sometimes a group of related tenants. A public cloud is off-site, while a private cloud can be on-site or off-site – or on-prem or off-prem, if you prefer.

Both Sides Now: Hybrid Clouds

Speaking of on-prem and off-prem, there are Hybrid Clouds or Hybrid Data Clouds depending on what you need. Both are based on the idea that you extend your local resources (typically on-prem) to the cloud (typically off-prem) as needed. This extension is controlled by software that decides, based on rules you define, what needs to be done where.

A Hybrid Data Cloud is specific to data. For example, you can set up a rule that says all accounting files that have not been touched in the last year are automatically moved off-prem to cloud storage. The files are still available; they are just no longer stored on your local systems. The rules can be defined to fit an organization’s workflow and data retention policies.

A Hybrid Cloud is similar to a Hybrid Data Cloud except it also extends compute. For example, at the end of the quarter, you can spin up order processing application instances off-prem as needed to add to your on-prem capacity. Of course, determining where the transactional data used and created by these applications resides can be an interesting systems design challenge.

Clouds in my Coffee: Fog

Typically, public and private clouds live in large buildings called data centers. Full of servers, networking equipment, and clean air, data centers need lots of power, lots of networking bandwidth, and lots of space. This often limits where data centers are located. The further away you are from a data center, the longer it generally takes to get your data to and from there. This is known as latency. That’s where “Fog” comes in.

Fog is often referred to as clouds close to the ground. Fog, in our cloud world, is basically having a “little” data center near you. This can make data storage and even cloud based processing faster for everyone nearby. Data, and less so processing, can be transferred to/from the Fog to the Cloud when time is less a factor. Data could also be aggregated in the Fog and sent to the Cloud. For example, your electric meter could report its minute-by-minute status to the Fog for diagnostic purposes. Then once a day the aggregated data could be send to the power company’s Cloud for billing purposes.

Another term used in place of Fog is Edge, as in computing at the Edge. In either case, a given cloud (data center) usually has multiple Edges (little data centers) connected to it. The connection between the Edge and the Cloud is sometimes known as the middle-mile. The network in the middle-mile can be less robust than that required to support a stand-alone data center. For example, the middle-mile can use 1 Gbps lines, versus a data center, which would require multiple 10 Gbps lines.

Heavy Clouds No Rain: Data

We’re all aware that we are creating, processing, and storing data faster than ever before. All of this data is stored in either a structured or more likely an unstructured way. Databases and data warehouses are structured ways to store data, but a vast amount of data is unstructured – meaning the schema and data access requirements are not known until the data is queried. A large pool of unstructured data in a flat architecture can be referred to as a Data Lake.

A Data Lake is often created so we can perform some type of “big data” analysis. In an over simplified example, let’s extend the lake metaphor a bit and ask the question; “how many fish are in our lake?” To get an answer, we take a sufficient sample of our lake’s water (data), count the number of fish we find, and extrapolate based on the size of the lake to get an answer within a given confidence interval.

A Data Lake is usually found in the cloud, an excellent place to store large amounts of non-transactional data. Watch out as this can lead to our data having too much Data Gravity or being locked in the Hotel California. This could also create a Data Silo, thereby making a potential data Lift-and-Shift impossible. Let me explain:

  • Data Gravity — Generally, the more data you collect in one spot, the harder it is to move. When you store data in a public cloud, you have to pay egress and/or network charges to download the data to another public cloud or even to your own on-premise systems. Some public cloud vendors charge a lot more than others, meaning that depending on your public cloud provider, your data could financially have a lot more gravity than you expected.
  • Hotel California — This is like Data Gravity but to a lesser scale. Your data is in the Hotel California if, to paraphrase, “your data can check out any time you want, but it can never leave.” If the cost of downloading your data is limiting the things you want to do with that data, then your data is in the Hotel California. Data is generally most valuable when used, and with cloud storage that can include archived data. This assumes of course that the archived data is readily available, and affordable, to download. When considering a cloud storage project always figure in the cost of using your own data.
  • Data Silo — Over the years, businesses have suffered from organizational silos as information is not shared between different groups, but instead needs to travel up to the top of the silo before it can be transferred to another silo. If your data is “trapped” in a given cloud by the cost it takes to share such data, then you may have a Data Silo, and that’s exactly opposite of what the cloud should do.
  • Lift-and-Shift — This term is used to define the movement of data or applications from one data center to another or from on-prem to off-prem systems. The move generally occurs all at once and once everything is moved, systems are operational and data is available at the new location with few, if any, changes. If your data has too much gravity or is locked in a hotel, a data lift-and-shift may break the bank.

I Can See Clearly Now

Hopefully, the cloudy terms we’ve covered are well, less cloudy. As we mentioned in the beginning, our compilation is just a start, so please feel free to add in your favorite cloud term in the comments section below and we’ll update this post with your contributions. Keep your entries “clean,” and please no words or phrases that are really adverts for your company. Thanks.

The post Cloud Babble: The Jargon of Cloud Storage appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.

Hello World Issue 4: Professional Development

Post Syndicated from Carrie Anne Philbin original https://www.raspberrypi.org/blog/hello-world-issue-4/

Another new year brings with it thoughts of setting goals and targets. Thankfully, there is a new issue of Hello World packed with practical advise to set you on the road to success.

Hello World is our magazine about computing and digital making for educators, and it’s a collaboration between the Raspberry Pi Foundation and Computing at School, which is part of the British Computing Society.

Hello World 4 Professional Development Raspberry Pi CAS

In issue 4, our international panel of educators and experts recommends approaches to continuing professional development in computer science education.

Approaches to professional development, and much more

With recommendations for more professional development in the Royal Society’s report, and government funding to support this, our cover feature explores some successful approaches. In addition, the issue is packed with other great resources, guides, features, and lesson plans to support educators.

Hello World 4 Professional Development Raspberry Pi CAS
Hello World 4 Professional Development Raspberry Pi CAS
Hello World 4 Professional Development Raspberry Pi CAS
Hello World 4 Professional Development Raspberry Pi CAS

Highlights include:

  • The Royal Society: After the Reboot — learn about the latest report and its findings about computing education
  • The Cyber Games — a new programme looking for the next generation of security experts
  • Engaging Students with Drones
  • Digital Literacy: Lost in Translation?
  • Object-oriented Coding with Python

Get your copy of Hello World 4

Hello World is available as a free Creative Commons download for anyone around the world who is interested in computer science and digital making education. You can get the latest issue as a PDF file straight from the Hello World website.

Thanks to the very generous sponsorship of BT, we are able to offer free print copies of the magazine to serving educators in the UK. It’s for teachers, Code Club volunteers, teaching assistants, teacher trainers, and others who help children and young people learn about computing and digital making. So remember to subscribe to have your free print magazine posted directly to your home — 6000 educators have already signed up to receive theirs!

Could you write for Hello World?

By sharing your knowledge and experience of working with young people to learn about computing, computer science, and digital making in Hello World, you will help inspire others to get involved. You will also help bring the power of digital making to more and more educators and learners.

The computing education community is full of people who lend their experience to help colleagues. Contributing to Hello World is a great way to take an active part in this supportive community, and you’ll be adding to a body of free, open-source learning resources that are available for anyone to use, adapt, and share. It’s also a tremendous platform to broadcast your work: Hello World digital versions alone have been downloaded more than 50000 times!

Wherever you are in the world, get in touch with us by emailing our editorial team about your article idea.

The post Hello World Issue 4: Professional Development appeared first on Raspberry Pi.

All the lights, all of the twinkly lights

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/all-of-the-lights/

Twinkly lights are to Christmas what pumpkins are to Halloween. And when you add a Raspberry Pi to your light show, the result instantly goes from “Meh, yeah.” to “OMG, wow!”

Here are some cool light-based Christmas projects to inspire you this weekend.

Raspberry Pi Christmas Lights

App-based light control

Christmas Tree Lights Demo

Project Code – https://github.com/eidolonFIRE/Christmas-Lights Raspberry Pi A+ ws2812b – https://smile.amazon.com/gp/product/B01H04YAIQ/ref=od_aui_detailpages00?ie=UTF8&psc=1 200w 5V supply – https://smile.amazon.com/gp/product/B01LZRIWZD/ref=od_aui_detailpages01?ie=UTF8&psc=1

In his Christmas lights project, Caleb Johnson uses an app as a control panel to switch between predefined displays. The full code is available on his GitHub, and it connects a Raspberry Pi A+ to a strip of programmable LEDs that change their pattern at the touch of a phone screen.

What’s great about this project, aside from the simplicity of its design, is the scope for extending it. Why not share the app with friends and family, allowing them to control your lights remotely? Or link the lights to social media so they are triggered by a specific hashtag, like in Alex Ellis’ #cheerlights project below.

Worldwide holiday #cheerlights

Holiday lights hack – 1$ Snowman + Raspberry Pi

Here we have a smart holiday light which will only run when it detects your presence in the room through a passive infrared PIR sensor. I’ve used hot glue for the fixings and an 8-LED NeoPixel strip connected to port 18.

Cheerlights, an online service created by Hans Scharler, allows makers to incorporate hashtag-controlled lighting into the projects. By tweeting the hashtag #cheerlights, followed by a colour, you can control a network of lights so that they are all displaying the same colour.

For his holiday light hack using Cheerlights, Alex incorporated the Pimoroni Blinkt! and a collection of cheap Christmas decorations to create cute light-up ornaments for the festive season.

To make your own, check out Alex’s blog post, and head to your local £1/$1 store for hackable decor. You could even link your Christmas tree and the trees of your family, syncing them all in one glorious, Santa-pleasing spectacular.

Outdoor decorations

DIY musical Xmas lights for beginners with raspberry pi

With just a few bucks of extra material, I walk you through converting your regular Christmas lights into a whole-house light show. The goal here is to go from scratch. Although this guide is intended for people who don’t know how to use linux at all and those who do alike, the focus is for people for whom linux and the raspberry pi are a complete mystery.

Looking to outdo your neighbours with your Christmas light show this year? YouTuber Makin’Things has created a beginners guide to setting up a Raspberry Pi–based musical light show for your facade, complete with information on soldering, wiring, and coding.

Once you’ve wrapped your house in metres and metres of lights and boosted your speakers so they can be heard for miles around, why not incorporate #cheerlights to make your outdoor decor interactive?

Still not enough? How about controlling your lights using a drum kit? Christian Kratky’s MIDI-Based Christmas Lights Animation system (or as I like to call it, House Rock) does exactly that.

Eye Of The Tiger (MIDI based christmas lights animation system prototype)

Project documentation and source code: https://www.hackster.io/cyborg-titanium-14/light-pi-1c88b0 The song is taken from: https://www.youtube.com/watch?v=G6r1dAire0Y

Any more?

We know these projects are just the tip of the iceberg when it comes to the Raspberry Pi–powered Christmas projects out there, and as always, we’d love you to share yours with us. So post a link in the comments below, or tag us on social media when posting your build photos, videos, and/or blog links. ‘Tis the season for sharing after all.

The post All the lights, all of the twinkly lights appeared first on Raspberry Pi.

Digital making for new parents

Post Syndicated from Carrie Anne Philbin original https://www.raspberrypi.org/blog/digital-making-for-new-parents/

Solving problems that are meaningful to us is at the core of our approach to teaching and learning about technology here at the Raspberry Pi Foundation. Over the last eight months, I’ve noticed that the types of digital making projects that motivate and engage me have changed (can’t think why). Always looking for ways to save money and automate my life and the lives of my loved ones, I’ve been thinking a lot about how digital making projects could be the new best friend of any new parent.

A baby, oblivious to the amount its parents have spent on stuff they never knew existed last year.
Image: sweet baby by MRef photography / CC BY-ND 2.0

Baby Monitor

I never knew how much equipment one small child needs until very recently. I also had no idea of the range of technology that is on offer to support you as a new parent to ensure the perfect environment outside of the womb. Baby monitors are at the top of this list. There are lots of Raspberry Pi baby monitor projects with a range of sensing functionality already in existence, and we’ve blogged about some of them before. They’re a great example of how an understanding of technology can open up a range of solutions that won’t break the bank. I’m looking forward to using all the capabilities of the Raspberry Pi to keep an eye on baby.

Baby name generator

Another surprising discovery was just how difficult it is to name a human being. Surprising because I can give a name to an inanimate object in less than three seconds, and come up with nicknames for colleagues in less than a day. My own offspring, though, and I draw a blank. The only solution: write a Python program to randomly generate names based on some parameters!

import names
from time import sleep
from guizero import App, ButtonGroup, Text, PushButton, TextBox

def get_name():
    boyname = names.get_first_name(gender='male')
    girlname = names.get_first_name(gender='female')
    othername = names.get_first_name()

    if babygender.get() == "male":
        name.set(str(boyname)+" "+str(babylastname.get()))
    elif babygender.get() == "female":
        name.set(str(girlname)+" "+str(babylastname.get()))
    else:
        name.set(str(othername)+" "+str(babylastname.get()))

app = App("Baby name generator")
surname_label = Text(app, "What is your surname?")
babylastname = TextBox(app, width=50)
babygender = ButtonGroup(app, options=[["boy", "male"], ["girl", "female"], ["all", "all"]], selected="male", horizontal=True)
intro = Text(app, "Your baby name could be")
name = Text(app, "")
button = PushButton(app, get_name, text="Generate me a name")

app.display()

Thanks to the names and GUIZero Python libraries, it is super simple to create, resolving any possible parent-to-be naming disputes in mere minutes.

Food, Poo, or Love?

I love data. Not just in Star Trek, but also more generally. Collecting and analysing data to understand my sleep patterns, my eating habits, how much exercise I do, and how much time I spend watching YouTube videos consumes much of my time. So of course I want to know lots about the little person we’ve made, long before he can use language to tell us himself.

I’m told that most newborns’ needs are quite simple: they want food, they want to be changed, or they just want some cuddles. I’m certain it’s more complicated than this, but it’s a good starting point for a data set, so stick with me here. I also wondered whether there might be a correlation between the amplitude of the cry and the type of need the baby has. A bit of an imprecise indicator, maybe, but fun to start to think about.

This build’s success is mostly thanks to Pimoroni’s Rainbow HAT, which, conveniently, has three capacitive touch buttons to record the newborn’s need, four fourteen-segment displays to display the words “FOOD”, “POO”, and “LOVE” when a button is pressed, and seven multicoloured LEDs to indicate the ferociousness of the baby’s cry in glorious technicolour. With the addition of a microphone, the ‘Food, Poo, Love Machine’ was born. Here it is in action:

Food Poo Love – Raspberry Pi Baby Monitor Project

Food Poo Love – The Raspberry Pi baby monitor project that allows you to track data on your new born baby.

Automatic Baby mobile

Another project that I’ve not had time to hack on, but that I think would be really awesome, is to automate a baby cot mobile. Imagine this one moving to the Star Trek theme music:

Image courtesy of Gisele Blaker Designs (check out her cool shop!)

Pretty awesome.

If you’ve got any more ideas for baby projects, do let me know. I’ll have a few months of nothing to do… right?

The post Digital making for new parents appeared first on Raspberry Pi.

E-Mail Tracking

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2017/12/e-mail_tracking_1.html

Good article on the history and practice of e-mail tracking:

The tech is pretty simple. Tracking clients embed a line of code in the body of an email­ — usually in a 1×1 pixel image, so tiny it’s invisible, but also in elements like hyperlinks and custom fonts. When a recipient opens the email, the tracking client recognizes that pixel has been downloaded, as well as where and on what device. Newsletter services, marketers, and advertisers have used the technique for years, to collect data about their open rates; major tech companies like Facebook and Twitter followed suit in their ongoing quest to profile and predict our behavior online.

But lately, a surprising­ — and growing­ — number of tracked emails are being sent not from corporations, but acquaintances. “We have been in touch with users that were tracked by their spouses, business partners, competitors,” says Florian Seroussi, the founder of OMC. “It’s the wild, wild west out there.”

According to OMC’s data, a full 19 percent of all “conversational” email is now tracked. That’s one in five of the emails you get from your friends. And you probably never noticed.

I admit it’s enticing. I would very much like the statistics that adding trackers to Crypto-Gram would give me. But I still don’t do it.

Pioneers winners: only you can save us

Post Syndicated from Erin Brindley original https://www.raspberrypi.org/blog/pioneers-winners-only-you-can-save-us/

She asked for help, and you came to her aid. Pioneers, the winners of the Only you can save us challenge have been picked!

Can you see me? Only YOU can save us!

I need your help. This is a call out for those between 11- and 16-years-old in the UK and Republic of Ireland. Something has gone very, very wrong and only you can save us. I’ve collected together as much information for you as I can. You’ll find it at http://www.raspberrypi.org/pioneers.

The challenge

In August we intercepted an emergency communication from a lonesome survivor. She seemed to be in quite a bit of trouble, and asked all you young people aged 11 to 16 to come up with something to help tackle the oncoming crisis, using whatever technology you had to hand. You had ten weeks to work in teams of two to five with an adult mentor to fulfil your mission.

The judges

We received your world-saving ideas, and our savvy survivor pulled together a ragtag bunch of apocalyptic experts to help us judge which ones would be the winning entries.

Dr Shini Somara

Dr Shini Somara is an advocate for STEM education and a mechanical engineer. She was host of The Health Show and has appeared in documentaries for the BBC, PBS Digital, and Sky. You can check out her work hosting Crash Course Physics on YouTube.

Prof Lewis Dartnell is an astrobiologist and author of the book The Knowledge: How to Rebuild Our World From Scratch.

Emma Stephenson has a background in aeronautical engineering and currently works in the Shell Foundation’s Access to Energy and Sustainable Mobility portfolio.

Currently sifting through the entries with the other judges of #makeyourideas with @raspberrypifoundation @_raspberrypi_

151 Likes, 3 Comments – Shini Somara (@drshinisomara) on Instagram: “Currently sifting through the entries with the other judges of #makeyourideas with…”

The winners

Our survivor is currently putting your entries to good use repairing, rebuilding, and defending her base. Our judges chose the following projects as outstanding examples of world-saving digital making.

Theme winner: Computatron

Raspberry Pioneers 2017 – Nerfus Dislikus Killer Robot

This is our entry to the pioneers ‘Only you can save us’ competition. Our team name is Computatrum. Hope you enjoy!

Are you facing an unknown enemy whose only weakness is Nerf bullets? Then this is the robot for you! We loved the especially apocalyptic feel of the Computatron’s cleverly hacked and repurposed elements. The team even used an old floppy disc mechanism to help fire their bullets!

Technically brilliant: Robot Apocalypse Committee

Pioneers Apocalypse 2017 – RationalPi

Thousands of lines of code… Many sheets of acrylic… A camera, touchscreen and fingerprint scanner… This is our entry into the Raspberry Pi Pioneers2017 ‘Only YOU can Save Us’ theme. When zombies or other survivors break into your base, you want a secure way of storing your crackers.

The Robot Apocalypse Committee is back, and this time they’ve brought cheese! The crew designed a cheese- and cracker-dispensing machine complete with face and fingerprint recognition to ensure those rations last until the next supply drop.

Best explanation: Pi Chasers

Tala – Raspberry Pi Pioneers Project

Hi! We are PiChasers and we entered the Raspberry Pi Pionners challenge last time when the theme was “Make it Outdoors!” but now we’ve been faced with another theme “Apocolypse”. We spent a while thinking of an original thing that would help in an apocolypse and decided upon a ‘text-only phone’ which uses local radio communication rather than cellular.

This text-based communication device encased in a tupperware container could be a lifesaver in a crisis! And luckily, the Pi Chasers produced an excellent video and amazing GitHub repo, ensuring that any and all survivors will be able to build their own in the safety of their base.

Most inspiring journey: Three Musketeers

Pioneers Entry – The Apocalypse

Pioneers Entry Team Name: The Three Musketeers Team Participants: James, Zach and Tom

We all know that zombies are terrible at geometry, and the Three Musketeers used this fact to their advantage when building their zombie security system. We were impressed to see the team working together to overcome the roadblocks they faced along the way.

We appreciate what you’re trying to do: Zombie Trolls

Zombie In The Middle

Uploaded by CDA Bodgers on 2017-12-01.

Playing piggy in the middle with zombies sure is a unique way of saving humankind from total extinction! We loved this project idea, and although the Zombie Trolls had a little trouble with their motors, we’re sure with a little more tinkering this zombie-fooling contraption could save us all.

Most awesome

Our judges also wanted to give a special commendation to the following teams for their equally awesome apocalypse-averting ideas:

  • PiRates, for their multifaceted zombie-proofing defence system and the high production value of their video
  • Byte them Pis, for their beautiful zombie-detecting doormat
  • Unatecxon, for their impressive bunker security system
  • Team Crompton, for their pressure-activated door system
  • Team Ernest, for their adventures in LEGO

The prizes

All our winning teams have secured exclusive digital maker boxes. These are jam-packed with tantalising tech to satisfy all tinkering needs, including:

Our theme winners have also secured themselves a place at Coolest Projects 2018 in Dublin, Ireland!

Thank you to everyone who got involved in this round of Pioneers. Look out for your awesome submission swag arriving in the mail!

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Remote Hack of a Boeing 757

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2017/12/remote_hack_of_.html

Last month, the DHS announced that it was able to remotely hack a Boeing 757:

“We got the airplane on Sept. 19, 2016. Two days later, I was successful in accomplishing a remote, non-cooperative, penetration,” said Robert Hickey, aviation program manager within the Cyber Security Division of the DHS Science and Technology (S&T) Directorate.

“[Which] means I didn’t have anybody touching the airplane, I didn’t have an insider threat. I stood off using typical stuff that could get through security and we were able to establish a presence on the systems of the aircraft.” Hickey said the details of the hack and the work his team are doing are classified, but said they accessed the aircraft’s systems through radio frequency communications, adding that, based on the RF configuration of most aircraft, “you can come to grips pretty quickly where we went” on the aircraft.

Treasure Trove of AACS 2.0 UHD Blu-Ray Keys Leak Online

Post Syndicated from Ernesto original https://torrentfreak.com/treasure-trove-of-aacs-2-0-uhd-blu-ray-keys-leak-online-171211/

Nowadays, movie buffs and videophiles find it hard to imagine a good viewing experience without UHD content, but disc rippers and pirates have remained on the sidelines for a long time.

Protected with strong AACS 2.0 encryption, UHD Blu-ray discs have long been one of the last bastions movie pirates had yet to breach.

This year there have been some major developments on this front, as full copies of UHD discs started to leak online. While it remained unclear how these were ripped, it was a definite milestone.

Just a few months ago another breakthrough came when a Russian company released a Windows tool called DeUHD that could rip UHD Blu-ray discs. Again, the method for obtaining the keys was not revealed.

Now there’s another setback for AACS LA, the licensing outfit founded by Warner Bros, Disney, Microsoft, Intel, and others. On various platforms around the Internet, copies of 72 AACS 2.0 keys are being shared.

The first mention we can find was posted a few days ago in a ten-year-old forum thread in the Doom9 forums. Since then it has been replicated a few times, without much fanfare.

The keys

The keys in question are confirmed to work and allow people to rip UHD Blu-ray discs of movies with freely available software such as MakeMKV. They are also different from the DeUHD list, so there are more people who know how to get them.

The full list of leaked keys includes movies such as Deadpool, Hancock, Passengers, Star Trek: Into Darkness, and The Martian. Some movies have multiple keys, likely as a result of different disc releases.

The leaked keys are also relevant for another reason. Ten years ago, a hacker leaked the AACS cryptographic key “09 F9” online which prompted the MPAA and AACS LA to issue DMCA takedown requests to sites where it surfaced.

This escalated into a censorship debate when Digg started removing articles that referenced the leak, triggering a massive backlash.

Thus fas the response to the AACS 2.0 leaks has been pretty tame, but it’s still early days. A user who posted the leaked keys on MyCe has already removed them due to possible copyright problems, so it’s definitely still a touchy subject.

The question that remains now is how the hacker managed to secure the keys, and if AACS 2.0 has been permanently breached.

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

Sean Hodgins’ video-playing Christmas ornament

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/sean-hodgins-ornament/

Standard Christmas tree ornaments are just so boring, always hanging there doing nothing. Yawn! Lucky for us, Sean Hodgins has created an ornament that plays classic nineties Christmas adverts, because of nostalgia.

YouTube Christmas Ornament! – Raspberry Pi Project

This Christmas ornament will really take you back…

Ingredients

Sean first 3D printed a small CRT-shaped ornament resembling the family television set in The Simpsons. He then got to work on the rest of the components.

Pi Zero and electronic components — Sean Hodgins Raspberry Pi Christmas ornament

All images featured in this blog post are c/o Sean Hodgins. Thanks, Sean!

The ornament uses a Raspberry Pi Zero W, 2.2″ TFT LCD screen, Mono Amp, LiPo battery, and speaker, plus the usual peripherals. Sean purposely assembled it with jumper wires and tape, so that he can reuse the components for another project after the festive season.

Clip of PowerBoost 1000 LiPo charger — Sean Hodgins Raspberry Pi Christmas ornament

By adding header pins to a PowerBoost 1000 LiPo charger, Sean was able to connect a switch to control the Pi’s power usage. This method is handy if you want to seal your Pi in a casing that blocks access to the power leads. From there, jumper wires connect the audio amplifier, LCD screen, and PowerBoost to the Zero W.

Code

Then, with Raspbian installed to an SD card and SSH enabled on the Zero W, Sean got the screen to work. The type of screen he used has both SPI and FBTFT enabled. And his next step was to set up the audio functionality with the help of an Adafruit tutorial.

Clip demoing Sean Hodgins Raspberry Pi Christmas ornament

For video playback, Sean installed mplayer before writing a program to extract video content from YouTube*. Once extracted, the video files are saved to the Raspberry Pi, allowing for seamless playback on the screen.

Construct

When fully assembled, the entire build fit snugly within the 3D-printed television set. And as a final touch, Sean added the cut-out lens of a rectangular magnifying glass to give the display the look of a curved CRT screen.

Clip of completed Sean Hodgins Raspberry Pi Christmas ornament in a tree

Then finally, the ornament hangs perfectly on the Christmas tree, up and running and spreading nostalgic warmth.

For more information on the build, check out the Instructables tutorial. And to see all of Sean’s builds, subscribe to his YouTube channel.

Make

If you’re looking for similar projects, have a look at this tutorial by Cabe Atwell for building a Pi-powered ornament that receives and displays text messages.

Have you created Raspberry Pi tree ornaments? Maybe you’ve 3D printed some of our own? We’d love to see what you’re doing with a Raspberry Pi this festive season, so make sure to share your projects with us, either in the comments below or via our social media channels.

 

*At this point, I should note that we don’t support the extraction of  video content from YouTube for your own use if you do not have the right permissions. However, since Sean’s device can play back any video, we think it would look great on your tree showing your own family videos from previous years. So, y’know, be good, be legal, and be festive.

The post Sean Hodgins’ video-playing Christmas ornament appeared first on Raspberry Pi.

The Raspberry Pi Christmas shopping list 2017

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/christmas-shopping-list-2017/

Looking for the perfect Christmas gift for a beloved maker in your life? Maybe you’d like to give a relative or friend a taste of the world of coding and Raspberry Pi? Whatever you’re looking for, the Raspberry Pi Christmas shopping list will point you in the right direction.

An ice-skating Raspberry Pi - The Raspberry Pi Christmas Shopping List 2017

For those getting started

Thinking about introducing someone special to the wonders of Raspberry Pi during the holidays? Although you can set up your Pi with peripherals from around your home, such as a mobile phone charger, your PC’s keyboard, and the old mouse dwelling in an office drawer, a starter kit is a nice all-in-one package for the budding coder.



Check out the starter kits from Raspberry Pi Approved Resellers such as Pimoroni, The Pi Hut, ModMyPi, Adafruit, CanaKit…the list is pretty long. Our products page will direct you to your closest reseller, or you can head to element14 to pick up the official Raspberry Pi Starter Kit.



You can also buy the Raspberry Pi Press’s brand-new Raspberry Pi Beginners Book, which includes a Raspberry Pi Zero W, a case, a ready-made SD card, and adapter cables.

Once you’ve presented a lucky person with their first Raspberry Pi, it’s time for them to spread their maker wings and learn some new skills.

MagPi Essentials books - The Raspberry Pi Christmas Shopping List 2017

To help them along, you could pick your favourite from among the Official Projects Book volume 3, The MagPi Essentials guides, and the brand-new third edition of Carrie Anne Philbin’s Adventures in Raspberry Pi. (She is super excited about this new edition!)

And you can always add a link to our free resources on the gift tag.

For the maker in your life

If you’re looking for something for a confident digital maker, you can’t go wrong with adding to their arsenal of electric and electronic bits and bobs that are no doubt cluttering drawers and boxes throughout their house.



Components such as servomotors, displays, and sensors are staples of the maker world. And when it comes to jumper wires, buttons, and LEDs, one can never have enough.



You could also consider getting your person a soldering iron, some helpings hands, or small tools such as a Dremel or screwdriver set.

And to make their life a little less messy, pop it all inside a Really Useful Box…because they’re really useful.



For kit makers

While some people like to dive into making head-first and to build whatever comes to mind, others enjoy working with kits.



The Naturebytes kit allows you to record the animal visitors of your garden with the help of a camera and a motion sensor. Footage of your local badgers, birds, deer, and more will be saved to an SD card, or tweeted or emailed to you if it’s in range of WiFi.

Cortec Tiny 4WD - The Raspberry Pi Christmas Shopping List 2017

Coretec’s Tiny 4WD is a kit for assembling a Pi Zero–powered remote-controlled robot at home. Not only is the robot adorable, building it also a great introduction to motors and wireless control.



Bare Conductive’s Touch Board Pro Kit offers everything you need to create interactive electronics projects using conductive paint.

Pi Hut Arcade Kit - The Raspberry Pi Christmas Shopping List 2017

Finally, why not help your favourite maker create their own gaming arcade using the Arcade Building Kit from The Pi Hut?

For the reader

For those who like to curl up with a good read, or spend too much of their day on public transport, a book or magazine subscription is the perfect treat.

For makers, hackers, and those interested in new technologies, our brand-new HackSpace magazine and the ever popular community magazine The MagPi are ideal. Both are available via a physical or digital subscription, and new subscribers to The MagPi also receive a free Raspberry Pi Zero W plus case.

Cover of CoderDojo Nano Make your own game

Marc Scott Beginner's Guide to Coding Book

You can also check out other publications from the Raspberry Pi family, including CoderDojo’s new CoderDojo Nano: Make Your Own Game, Eben Upton and Gareth Halfacree’s Raspberry Pi User Guide, and Marc Scott’s A Beginner’s Guide to Coding. And have I mentioned Carrie Anne’s Adventures in Raspberry Pi yet?

Stocking fillers for everyone

Looking for something small to keep your loved ones occupied on Christmas morning? Or do you have to buy a Secret Santa gift for the office tech? Here are some wonderful stocking fillers to fill your boots with this season.

Pi Hut 3D Christmas Tree - The Raspberry Pi Christmas Shopping List 2017

The Pi Hut 3D Xmas Tree: available as both a pre-soldered and a DIY version, this gadget will work with any 40-pin Raspberry Pi and allows you to create your own mini light show.



Google AIY Voice kit: build your own home assistant using a Raspberry Pi, the MagPi Essentials guide, and this brand-new kit. “Google, play Mariah Carey again…”



Pimoroni’s Raspberry Pi Zero W Project Kits offer everything you need, including the Pi, to make your own time-lapse cameras, music players, and more.



The official Raspberry Pi Sense HAT, Camera Module, and cases for the Pi 3 and Pi Zero will complete the collection of any Raspberry Pi owner, while also opening up exciting project opportunities.

STEAM gifts that everyone will love

Awesome Astronauts | Building LEGO’s Women of NASA!

LEGO Idea’s bought out this amazing ‘Women of NASA’ set, and I thought it would be fun to build, play and learn from these inspiring women! First up, let’s discover a little more about Sally Ride and Mae Jemison, two AWESOME ASTRONAUTS!

Treat the kids, and big kids, in your life to the newest LEGO Ideas set, the Women of NASA — starring Nancy Grace Roman, Margaret Hamilton, Sally Ride, and Mae Jemison!



Explore the world of wearables with Pimoroni’s sewable, hackable, wearable, adorable Bearables kits.



Add lights and motors to paper creations with the Activating Origami Kit, available from The Pi Hut.




We all loved Hidden Figures, and the STEAM enthusiast you know will do too. The film’s available on DVD, and you can also buy the original book, along with other fascinating non-fiction such as Rebecca Skloot’s The Immortal Life of Henrietta Lacks, Rachel Ignotofsky’s Women in Science, and Sydney Padua’s (mostly true) The Thrilling Adventures of Lovelace and Babbage.

Have we missed anything?

With so many amazing kits, HATs, and books available from members of the Raspberry Pi community, it’s hard to only pick a few. Have you found something splendid for the maker in your life? Maybe you’ve created your own kit that uses the Raspberry Pi? Share your favourites with us in the comments below or via our social media accounts.

The post The Raspberry Pi Christmas shopping list 2017 appeared first on Raspberry Pi.

Game night 1: Lisa, Lisa, MOOP

Post Syndicated from Eevee original https://eev.ee/blog/2017/12/05/game-night-1-lisa-lisa-moop/

For the last few weeks, glip (my partner) and I have spent a couple hours most nights playing indie games together. We started out intending to play a short list of games that had been recommended to glip, but this turns out to be a nice way to wind down, so we’ve been keeping it up and clicking on whatever looks interesting in the itch app.

Most of the games are small and made by one or two people, so they tend to be pretty tightly scoped and focus on a few particular kinds of details. I’ve found myself having brain thoughts about all that, so I thought I’d write some of them down.

I also know that some people (cough) tend not to play games they’ve never heard of, even if they want something new to play. If that’s you, feel free to play some of these, now that you’ve heard of them!

Also, I’m still figuring the format out here, so let me know if this is interesting or if you hope I never do it again!

First up:

  • Lisa: The Painful
  • Lisa: The Joyful
  • MOOP

These are impressions, not reviews. I try to avoid major/ending spoilers, but big plot points do tend to leave impressions.

Lisa: The Painful

long · classic rpg · dec 2014 · lin/mac/win · $10 on itch or steam · website

(cw: basically everything??)

Lisa: The Painful is true to its name. I hesitate to describe it as fun, exactly, but I’m glad we played it.

Everything about the game is dark. It’s a (somewhat loose) sequel to another game called Lisa, whose titular character ultimately commits suicide; her body hanging from a noose is the title screen for this game.

Ah, but don’t worry, it gets worse. This game takes place in a post-apocalyptic wasteland, where every female human — women, children, babies — is dead. You play as Brad (Lisa’s brother), who has discovered the lone exception: a baby girl he names Buddy and raises like a daughter. Now, Buddy has been kidnapped, and you have to go rescue her, presumably from being raped.

Ah, but don’t worry, it gets worse.


I’ve had a hard time putting my thoughts in order here, because so much of what stuck with me is the way the game entangles the plot with the mechanics.

I love that kind of thing, but it’s so hard to do well. I can’t really explain why, but I feel like most attempts to do it fall flat — they have a glimmer of an idea, but they don’t integrate it well enough, or they don’t run nearly as far as they could have. I often get the same feeling as, say, a hyped-up big moral choice that turns out to be picking “yes” or “no” from a menu. The idea is there, but the execution is so flimsy that it leaves no impact on me at all.

An obvious recent success here is Undertale, where the entire story is about violence and whether you choose to engage or avoid it (and whether you can do that). If you choose to eschew violence, not only does the game become more difficult, it arguably becomes a different game entirely. Granted, the contrast is lost if you (like me) tried to play as a pacifist from the very beginning. I do feel that you could go further with the idea than Undertale, but Undertale itself doesn’t feel incomplete.

Christ, I’m not even talking about the right game any more.

Okay, so: this game is a “classic” RPG, by which I mean, it was made with RPG Maker. (It’s kinda funny that RPG Maker was designed to emulate a very popular battle style, and now the only games that use that style are… made with RPG Maker.) The main loop, on the surface, is standard RPG fare: you walk around various places, talk to people, solve puzzles, recruit party members, and get into turn-based fights.

Now, Brad is addicted to a drug called Joy. He will regularly go into withdrawal, which manifests in the game as a status effect that cuts his stats (even his max HP!) dramatically.

It is really, really, incredibly inconvenient. And therein lies the genius here. The game could have simply told me that Brad is an addict, and I don’t think I would’ve cared too much. An addiction to a fantasy drug in a wasteland doesn’t mean anything to me, especially about this tiny sprite man I just met, so I would’ve filed this away as a sterile fact and forgotten about it. By making his addiction affect me, I’m now invested in it. I wish Brad weren’t addicted, even if only because it’s annoying. I found a party member once who turned out to have the same addiction, and I felt dread just from seeing the icon for the status effect. I’ve been looped into the events of this story through the medium I use to interact with it: the game.

It’s a really good use of games as a medium. Even before I’m invested in the characters, I’m invested in what’s happening to them, because it impacts the game!

Incidentally, you can get Joy as an item, which will temporarily cure your withdrawal… but you mostly find it by looting the corpses of grotesque mutant flesh horrors you encounter. I don’t think the game would have the player abruptly mutate out of nowhere, but I wasn’t about to find out, either. We never took any.


Virtually every staple of the RPG genre has been played with in some way to tie it into the theme/setting. I love it, and I think it works so well precisely because it plays with expectations of how RPGs usually work.

Most obviously, the game is a sidescroller, not top-down. You can’t jump freely, but you can hop onto one-tile-high boxes and climb ropes. You can also drop off off ledges… but your entire party will take fall damage, which gets rapidly more severe the further you fall.

This wouldn’t be too much of a problem, except that healing is hard to come by for most of the game. Several hub areas have campfires you can sleep next to to restore all your health and MP, but when you wake up, something will have happened to you. Maybe just a weird cutscene, or maybe one of your party members has decided to leave permanently.

Okay, so use healing items instead? Good luck; money is also hard to come by, and honestly so are shops, and many of the healing items are woefully underpowered.

Grind for money? Good luck there, too! While the game has plenty of battles, virtually every enemy is a unique overworld human who only appears once, and then is dead, because you killed him. Only a handful of places have unlimited random encounters, and grinding is not especially pleasant.

The “best” way to get a reliable heal is to savescum — save the game, sleep by the campfire, and reload if you don’t like what you wake up to.

In a similar vein, there’s a part of the game where you’re forced to play Russian Roulette. You choose a party member; he and an opponent will take turns shooting themselves in the head until someone finds a loaded chamber. If your party member loses, he is dead. And you have to keep playing until you win three times, so there’s no upper limit on how many people you might lose. I couldn’t find any way to influence who won, so I just had to savescum for a good half hour until I made it through with minimal losses.

It was maddening, but also a really good idea. Games don’t often incorporate the existence of saves into the gameplay, and when they do, they usually break the fourth wall and get all meta about it. Saves are never acknowledged in-universe here (aside from the existence of save points), but surely these parts of the game were designed knowing that the best way through them is by reloading. It’s rarely done, it can easily feel unfair, and it drove me up the wall — but it was certainly painful, as intended, and I kinda love that.

(Naturally, I’m told there’s a hard mode, where you can only use each save point once.)

The game also drives home the finality of death much better than most. It’s not hard to overlook the death of a redshirt, a character with a bit part who simply doesn’t appear any more. This game permanently kills your party members. Russian Roulette isn’t even the only way you can lose them! Multiple cutscenes force you to choose between losing a life or some other drastic consequence. (Even better, you can try to fight the person forcing this choice on you, and he will decimate you.) As the game progresses, you start to encounter enemies who can simply one-shot murder your party members.

It’s such a great angle. Just like with Brad’s withdrawal, you don’t want to avoid their deaths because it’d be emotional — there are dozens of party members you can recruit (though we only found a fraction of them), and most of them you only know a paragraph about — but because it would inconvenience you personally. Chances are, you have your strongest dudes in your party at any given time, so losing one of them sucks. And with few random encounters, you can’t just grind someone else up to an appropriate level; it feels like there’s a finite amount of XP in the game, and if someone high-level dies, you’ve lost all the XP that went into them.


The battles themselves are fairly straightforward. You can attack normally or use a special move that costs MP. SP? Some kind of points.

Two things in particular stand out. One I mentioned above: the vast majority of the encounters are one-time affairs against distinct named NPCs, who you then never see again, because they are dead, because you killed them.

The other is the somewhat unusual set of status effects. The staples like poison and sleep are here, but don’t show up all that often; more frequent are statuses like weird, drunk, stink, or cool. If you do take Joy (which also cures depression), you become joyed for a short time.

The game plays with these in a few neat ways, besides just Brad’s withdrawal. Some party members have a status like stink or cool permanently. Some battles are against people who don’t want to fight at all — and so they’ll spend most of the battle crying, purely for flavor impact. Seeing that for the first time hit me pretty hard; until then we’d only seen crying as a mechanical side effect of having sand kicked in one’s face.


The game does drag on a bit. I think we poured 10 in-game hours into it, which doesn’t count time spent reloading. It doesn’t help that you walk not super fast.

My biggest problem was with getting my bearings; I’m sure we spent a lot of that time wandering around accomplishing nothing. Most of the world is focused around one of a few hub areas, and once you’ve completed one hub, you can move onto the next one. That’s fine. Trouble is, you can go any of a dozen different directions from each hub, and most of those directions will lead you to very similar-looking hills built out of the same tiny handful of tiles. The connections between places are mostly cave entrances, which also largely look the same. Combine that with needing to backtrack for puzzle or progression reasons, and it’s incredibly difficult to keep track of where you’ve been, what you’ve done, and where you need to go next.

I don’t know that the game is wrong here; the aesthetic and world layout are fantastic at conveying a desolate wasteland. I wouldn’t even be surprised if the navigation were deliberately designed this way. (On the other hand, assuming every annoyance in a despair-ridden game is deliberate might be giving it too much credit.) But damn it’s still frustrating.

I felt a little lost in the battle system, too. Towards the end of the game, Brad in particular had over a dozen skills he could use, but I still couldn’t confidently tell you which were the strongest. New skills sometimes appear in the middle of the list or cost less than previous skills, and the game doesn’t outright tell you how much damage any of them do. I know this is the “classic RPG” style, and I don’t think it was hugely inconvenient, but it feels weird to barely know how my own skills work. I think this puts me off getting into new RPGs, just generally; there’s a whole new set of things I have to learn about, and games in this style often won’t just tell me anything, so there’s this whole separate meta-puzzle to figure out before I can play the actual game effectively.

Also, the sound could use a little bit of… mastering? Some music and sound effects are significantly louder and screechier than others. Painful, you could say.


The world is full of side characters with their own stuff going on, which is also something I love seeing in games; too often, the whole world feels like an obstacle course specifically designed for you.

Also, many of those characters are, well, not great people. Really, most of the game is kinda fucked up. Consider: the weird status effect is most commonly inflicted by the “Grope” skill. It makes you feel weird, you see. Oh, and the currency is porn magazines.

And then there are the gangs, the various spins on sex clubs, the forceful drug kingpins, and the overall violence that permeates everything (you stumble upon an alarming number of corpses). The game neither condones nor condemns any of this; it simply offers some ideas of how people might behave at the end of the world. It’s certainly the grittiest interpretation I’ve seen.

I don’t usually like post-apocalypses, because they try to have these very hopeful stories, but then at the end the world is still a blighted hellscape so what was the point of any of that? I like this game much better for being a blighted hellscape throughout. The story is worth following to see where it goes, not just because you expect everything wrapped up neatly at the end.

…I realize I’ve made this game sound monumentally depressing throughout, but it manages to pack in a lot of funny moments as well, from the subtle to the overt. In retrospect, it’s actually really good at balancing the mood so it doesn’t get too depressing. If nothing else, it’s hilarious to watch this gruff, solemn, battle-scarred, middle-aged man pedal around on a kid’s bike he found.


An obvious theme of the game is despair, but the more I think about it, the more I wonder if ambiguity is a theme as well. It certainly fits the confusing geography.

Even the premise is a little ambiguous. Is/was Olathe a city, a country, a whole planet? Did the apocalypse affect only Olathe, or the whole world? Does it matter in an RPG, where the only world that exists is the one mapped out within the game?

Towards the end of the game, you catch up with Buddy, but she rejects you, apparently resentful that you kept her hidden away for her entire life. Brad presses on anyway, insisting on protecting her.

At that point I wasn’t sure I was still on Brad’s side. But he’s not wrong, either. Is he? Maybe it depends on how old Buddy is — but the game never tells us. Her sprite is a bit smaller than the men’s, but it’s hard to gauge much from small exaggerated sprites, and she might just be shorter. In the beginning of the game, she was doing kid-like drawings, but we don’t know how much time passed after that. Everyone seems to take for granted that she’s capable of bearing children, and she talks like an adult. So is she old enough to be making this decision, or young enough for parent figure Brad to overrule her? What is the appropriate age of agency, anyway, when you’re the last girl/woman left more than a decade after the end of the world?

Can you repopulate a species with only one woman, anyway?


Well, that went on a bit longer than I intended. This game has a lot of small touches that stood out to me, and they all wove together very well.

Should you play it? I have absolutely no idea.

FINAL SCORE: 1 out of 6 chambers

Lisa: The Joyful

fairly short · classic rpg · aug 2015 · lin/mac/win · $5 on itch or steam

Surprise! There’s a third game to round out this trilogy.

Lisa: The Joyful is much shorter, maybe three hours long — enough to be played in a night rather than over the better part of a week.

This one picks up immediately after the end of Painful, with you now playing as Buddy. It takes a drastic turn early on: Buddy decides that, rather than hide from the world, she must conquer it. She sets out to murder all the big bosses and become queen.

The battle system has been inherited from the previous game, but battles are much more straightforward this time around. You can’t recruit any party members; for much of the game, it’s just you and a sword.

There is a catch! Of course.

The catch is that you do not have enough health to survive most boss battles without healing. With no party members, you cannot heal via skills. I don’t think you could buy healing items anywhere, either. You have a few when the game begins, but once you run out, that’s it.

Except… you also have… some Joy. Which restores you to full health and also makes you crit with every hit. And drops off of several enemies.

We didn’t even recognize Joy as a healing item at first, since we never used it in Painful; it’s description simply says that it makes you feel nothing, and we’d assumed the whole point of it was to stave off withdrawal, which Buddy doesn’t experience. Luckily, the game provided a hint in the form of an NPC who offers to switch on easy mode:

What’s that? Bad guys too tough? Not enough jerky? You don’t want to take Joy!? Say no more, you’ve come to the right place!

So the game is aware that it’s unfairly difficult, and it’s deliberately forcing you to take Joy, and it is in fact entirely constructed around this concept. I guess the title is a pretty good hint, too.

I don’t feel quite as strongly about Joyful as I do about Painful. (Admittedly, I was really tired and starting to doze off towards the end of Joyful.) Once you get that the gimmick is to force you to use Joy, the game basically reduces to a moderate-difficulty boss rush. Other than that, the only thing that stood out to me mechanically was that Buddy learns a skill where she lifts her shirt to inflict flustered as a status effect — kind of a lingering echo of how outrageous the previous game could be.

You do get a healthy serving of plot, which is nice and ties a few things together. I wouldn’t say it exactly wraps up the story, but it doesn’t feel like it’s missing anything either; it’s exactly as murky as you’d expect.

I think it’s worth playing Joyful if you’ve played Painful. It just didn’t have the same impact on me. It probably doesn’t help that I don’t like Buddy as a person. She seems cold, violent, and cruel. Appropriate for the world and a product of her environment, I suppose.

FINAL SCORE: 300 Mags

MOOP

fairly short · inventory game · nov 2017 · win · free on itch

Finally, as something of a palate cleanser, we have MOOP: a delightful and charming little inventory game.

I don’t think “inventory game” is a real genre, but I mean the kind of game where you go around collecting items and using them in the right place. Puzzle-driven, but with “puzzles” that can largely be solved by simply trying everything everywhere. I’d put a lot of point and click adventures in the same category, despite having a radically different interface. Is that fair? Yes, because it’s my blog.

MOOP was almost certainly also made in RPG Maker, but it breaks the mold in a very different way by not being an RPG. There are no battles whatsoever, only interactions on the overworld; you progress solely via dialogue and puzzle-solving. Examining something gives you a short menu of verbs — use, talk, get — reminiscent of interactive fiction, or perhaps the graphical “adventure” games that took inspiration from interactive fiction. (God, “adventure game” is the worst phrase. Every game is an adventure! It doesn’t mean anything!)

Everything about the game is extremely chill. I love the monochrome aesthetic combined with a large screen resolution; it feels like I’m peeking into an alternate universe where the Game Boy got bigger but never gained color. I played halfway through the game before realizing that the protagonist (Moop) doesn’t have a walk animation; they simply slide around. Somehow, it works.

The puzzles are a little clever, yet low-pressure; the world is small enough that you can examine everything again if you get stuck, and there’s no way to lose or be set back. The music is lovely, too. It just feels good to wander around in a world that manages to make sepia look very pretty.

The story manages to pack a lot into a very short time. It’s… gosh, I don’t know. It has a very distinct texture to it that I’m not sure I’ve seen before. The plot weaves through several major events that each have very different moods, and it moves very quickly — but it’s well-written and doesn’t feel rushed or disjoint. It’s lighthearted, but takes itself seriously enough for me to get invested. It’s fucking witchcraft.

I think there was even a non-binary character! Just kinda nonchalantly in there. Awesome.

What a happy, charming game. Play if you would like to be happy and charmed.

FINAL SCORE: 1 waxing moon

Glenn’s Take on re:Invent Part 2

Post Syndicated from Glenn Gore original https://aws.amazon.com/blogs/architecture/glenns-take-on-reinvent-part-2/

Glenn Gore here, Chief Architect for AWS. I’m in Las Vegas this week — with 43K others — for re:Invent 2017. We’ve got a lot of exciting announcements this week. I’m going to check in to the Architecture blog with my take on what’s interesting about some of the announcements from an cloud architectural perspective. My first post can be found here.

The Media and Entertainment industry has been a rapid adopter of AWS due to the scale, reliability, and low costs of our services. This has enabled customers to create new, online, digital experiences for their viewers ranging from broadcast to streaming to Over-the-Top (OTT) services that can be a combination of live, scheduled, or ad-hoc viewing, while supporting devices ranging from high-def TVs to mobile devices. Creating an end-to-end video service requires many different components often sourced from different vendors with different licensing models, which creates a complex architecture and a complex environment to support operationally.

AWS Media Services
Based on customer feedback, we have developed AWS Media Services to help simplify distribution of video content. AWS Media Services is comprised of five individual services that can either be used together to provide an end-to-end service or individually to work within existing deployments: AWS Elemental MediaConvert, AWS Elemental MediaLive, AWS Elemental MediaPackage, AWS Elemental MediaStore and AWS Elemental MediaTailor. These services can help you with everything from storing content safely and durably to setting up a live-streaming event in minutes without having to be concerned about the underlying infrastructure and scalability of the stream itself.

In my role, I participate in many AWS and industry events and often work with the production and event teams that put these shows together. With all the logistical tasks they have to deal with, the biggest question is often: “Will the live stream work?” Compounding this fear is the reality that, as users, we are also quick to jump on social media and make noise when a live stream drops while we are following along remotely. Worse is when I see event organizers actively selecting not to live stream content because of the risk of failure and and exposure — leading them to decide to take the safe option and not stream at all.

With AWS Media Services addressing many of the issues around putting together a high-quality media service, live streaming, and providing access to a library of content through a variety of mechanisms, I can’t wait to see more event teams use live streaming without the concern and worry I’ve seen in the past. I am excited for what this also means for non-media companies, as video becomes an increasingly common way of sharing information and adding a more personalized touch to internally- and externally-facing content.

AWS Media Services will allow you to focus more on the content and not worry about the platform. Awesome!

Amazon Neptune
As a civilization, we have been developing new ways to record and store information and model the relationships between sets of information for more than a thousand years. Government census data, tax records, births, deaths, and marriages were all recorded on medium ranging from knotted cords in the Inca civilization, clay tablets in ancient Babylon, to written texts in Western Europe during the late Middle Ages.

One of the first challenges of computing was figuring out how to store and work with vast amounts of information in a programmatic way, especially as the volume of information was increasing at a faster rate than ever before. We have seen different generations of how to organize this information in some form of database, ranging from flat files to the Information Management System (IMS) used in the 1960s for the Apollo space program, to the rise of the relational database management system (RDBMS) in the 1970s. These innovations drove a lot of subsequent innovations in information management and application development as we were able to move from thousands of records to millions and billions.

Today, as architects and developers, we have a vast variety of database technologies to select from, which have different characteristics that are optimized for different use cases:

  • Relational databases are well understood after decades of use in the majority of companies who required a database to store information. Amazon Relational Database (Amazon RDS) supports many popular relational database engines such as MySQL, Microsoft SQL Server, PostgreSQL, MariaDB, and Oracle. We have even brought the traditional RDBMS into the cloud world through Amazon Aurora, which provides MySQL and PostgreSQL support with the performance and reliability of commercial-grade databases at 1/10th the cost.
  • Non-relational databases (NoSQL) provided a simpler method of storing and retrieving information that was often faster and more scalable than traditional RDBMS technology. The concept of non-relational databases has existed since the 1960s but really took off in the early 2000s with the rise of web-based applications that required performance and scalability that relational databases struggled with at the time. AWS published this Dynamo whitepaper in 2007, with DynamoDB launching as a service in 2012. DynamoDB has quickly become one of the critical design elements for many of our customers who are building highly-scalable applications on AWS. We continue to innovate with DynamoDB, and this week launched global tables and on-demand backup at re:Invent 2017. DynamoDB excels in a variety of use cases, such as tracking of session information for popular websites, shopping cart information on e-commerce sites, and keeping track of gamers’ high scores in mobile gaming applications, for example.
  • Graph databases focus on the relationship between data items in the store. With a graph database, we work with nodes, edges, and properties to represent data, relationships, and information. Graph databases are designed to make it easy and fast to traverse and retrieve complex hierarchical data models. Graph databases share some concepts from the NoSQL family of databases such as key-value pairs (properties) and the use of a non-SQL query language such as Gremlin. Graph databases are commonly used for social networking, recommendation engines, fraud detection, and knowledge graphs. We released Amazon Neptune to help simplify the provisioning and management of graph databases as we believe that graph databases are going to enable the next generation of smart applications.

A common use case I am hearing every week as I talk to customers is how to incorporate chatbots within their organizations. Amazon Lex and Amazon Polly have made it easy for customers to experiment and build chatbots for a wide range of scenarios, but one of the missing pieces of the puzzle was how to model decision trees and and knowledge graphs so the chatbot could guide the conversation in an intelligent manner.

Graph databases are ideal for this particular use case, and having Amazon Neptune simplifies the deployment of a graph database while providing high performance, scalability, availability, and durability as a managed service. Security of your graph database is critical. To help ensure this, you can store your encrypted data by running AWS in Amazon Neptune within your Amazon Virtual Private Cloud (Amazon VPC) and using encryption at rest integrated with AWS Key Management Service (AWS KMS). Neptune also supports Amazon VPC and AWS Identity and Access Management (AWS IAM) to help further protect and restrict access.

Our customers now have the choice of many different database technologies to ensure that they can optimize each application and service for their specific needs. Just as DynamoDB has unlocked and enabled many new workloads that weren’t possible in relational databases, I can’t wait to see what new innovations and capabilities are enabled from graph databases as they become easier to use through Amazon Neptune.

Look for more on DynamoDB and Amazon S3 from me on Monday.

 

Glenn at Tour de Mont Blanc

 

 

Stretch for PCs and Macs, and a Raspbian update

Post Syndicated from Simon Long original https://www.raspberrypi.org/blog/stretch-pcs-macs-raspbian-update/

Today, we are launching the first Debian Stretch release of the Raspberry Pi Desktop for PCs and Macs, and we’re also releasing the latest version of Raspbian Stretch for your Pi.

Raspberry Pi Desktop Stretch splash screen

For PCs and Macs

When we released our custom desktop environment on Debian for PCs and Macs last year, we were slightly taken aback by how popular it turned out to be. We really only created it as a result of one of those “Wouldn’t it be cool if…” conversations we sometimes have in the office, so we were delighted by the Pi community’s reaction.

Seeing how keen people were on the x86 version, we decided that we were going to try to keep releasing it alongside Raspbian, with the ultimate aim being to make simultaneous releases of both. This proved to be tricky, particularly with the move from the Jessie version of Debian to the Stretch version this year. However, we have now finished the job of porting all the custom code in Raspbian Stretch to Debian, and so the first Debian Stretch release of the Raspberry Pi Desktop for your PC or Mac is available from today.

The new Stretch releases

As with the Jessie release, you can either run this as a live image from a DVD, USB stick, or SD card or install it as the native operating system on the hard drive of an old laptop or desktop computer. Please note that installing this software will erase anything else on the hard drive — do not install this over a machine running Windows or macOS that you still need to use for its original purpose! It is, however, safe to boot a live image on such a machine, since your hard drive will not be touched by this.

We’re also pleased to announce that we are releasing the latest version of Raspbian Stretch for your Pi today. The Pi and PC versions are largely identical: as before, there are a few applications (such as Mathematica) which are exclusive to the Pi, but the user interface, desktop, and most applications will be exactly the same.

For Raspbian, this new release is mostly bug fixes and tweaks over the previous Stretch release, but there are one or two changes you might notice.

File manager

The file manager included as part of the LXDE desktop (on which our desktop is based) is a program called PCManFM, and it’s very feature-rich; there’s not much you can’t do in it. However, having used it for a few years, we felt that it was perhaps more complex than it needed to be — the sheer number of menu options and choices made some common operations more awkward than they needed to be. So to try to make file management easier, we have implemented a cut-down mode for the file manager.

Raspberry Pi Desktop Stretch - file manager

Most of the changes are to do with the menus. We’ve removed a lot of options that most people are unlikely to change, and moved some other options into the Preferences screen rather than the menus. The two most common settings people tend to change — how icons are displayed and sorted — are now options on the toolbar and in a top-level menu rather than hidden away in submenus.

The sidebar now only shows a single hierarchical view of the file system, and we’ve tidied the toolbar and updated the icons to make them match our house style. We’ve removed the option for a tabbed interface, and we’ve stomped a few bugs as well.

One final change was to make it possible to rename a file just by clicking on its icon to highlight it, and then clicking on its name. This is the way renaming works on both Windows and macOS, and it’s always seemed slightly awkward that Unix desktop environments tend not to support it.

As with most of the other changes we’ve made to the desktop over the last few years, the intention is to make it simpler to use, and to ease the transition from non-Unix environments. But if you really don’t like what we’ve done and long for the old file manager, just untick the box for Display simplified user interface and menus in the Layout page of Preferences, and everything will be back the way it was!

Raspberry Pi Desktop Stretch - preferences GUI

Battery indicator for laptops

One important feature missing from the previous release was an indication of the amount of battery life. Eben runs our desktop on his Mac, and he was becoming slightly irritated by having to keep rebooting into macOS just to check whether his battery was about to die — so fixing this was a priority!

We’ve added a battery status icon to the taskbar; this shows current percentage charge, along with whether the battery is charging, discharging, or connected to the mains. When you hover over the icon with the mouse pointer, a tooltip with more details appears, including the time remaining if the battery can provide this information.

Raspberry Pi Desktop Stretch - battery indicator

While this battery monitor is mainly intended for the PC version, it also supports the first-generation pi-top — to see it, you’ll only need to make sure that I2C is enabled in Configuration. A future release will support the new second-generation pi-top.

New PC applications

We have included a couple of new applications in the PC version. One is called PiServer — this allows you to set up an operating system, such as Raspbian, on the PC which can then be shared by a number of Pi clients networked to it. It is intended to make it easy for classrooms to have multiple Pis all running exactly the same software, and for the teacher to have control over how the software is installed and used. PiServer is quite a clever piece of software, and it’ll be covered in more detail in another blog post in December.

We’ve also added an application which allows you to easily use the GPIO pins of a Pi Zero connected via USB to a PC in applications using Scratch or Python. This makes it possible to run the same physical computing projects on the PC as you do on a Pi! Again, we’ll tell you more in a separate blog post this month.

Both of these applications are included as standard on the PC image, but not on the Raspbian image. You can run them on a Pi if you want — both can be installed from apt.

How to get the new versions

New images for both Raspbian and Debian versions are available from the Downloads page.

It is possible to update existing installations of both Raspbian and Debian versions. For Raspbian, this is easy: just open a terminal window and enter

sudo apt-get update
sudo apt-get dist-upgrade

Updating Raspbian on your Raspberry Pi

How to update to the latest version of Raspbian on your Raspberry Pi. Download Raspbian here: More information on the latest version of Raspbian: Buy a Raspberry Pi:

It is slightly more complex for the PC version, as the previous release was based around Debian Jessie. You will need to edit the files /etc/apt/sources.list and /etc/apt/sources.list.d/raspi.list, using sudo to do so. In both files, change every occurrence of the word “jessie” to “stretch”. When that’s done, do the following:

sudo apt-get update 
sudo dpkg --force-depends -r libwebkitgtk-3.0-common
sudo apt-get -f install
sudo apt-get dist-upgrade
sudo apt-get install python3-thonny
sudo apt-get install sonic-pi=2.10.0~repack-rpt1+2
sudo apt-get install piserver
sudo apt-get install usbbootgui

At several points during the upgrade process, you will be asked if you want to keep the current version of a configuration file or to install the package maintainer’s version. In every case, keep the existing version, which is the default option. The update may take an hour or so, depending on your network connection.

As with all software updates, there is the possibility that something may go wrong during the process, which could lead to your operating system becoming corrupted. Therefore, we always recommend making a backup first.

Enjoy the new versions, and do let us know any feedback you have in the comments or on the forums!

The post Stretch for PCs and Macs, and a Raspbian update appeared first on Raspberry Pi.

GDPR – A Practical Guide For Developers

Post Syndicated from Bozho original https://techblog.bozho.net/gdpr-practical-guide-developers/

You’ve probably heard about GDPR. The new European data protection regulation that applies practically to everyone. Especially if you are working in a big company, it’s most likely that there’s already a process for gettign your systems in compliance with the regulation.

The regulation is basically a law that must be followed in all European countries (but also applies to non-EU companies that have users in the EU). In this particular case, it applies to companies that are not registered in Europe, but are having European customers. So that’s most companies. I will not go into yet another “12 facts about GDPR” or “7 myths about GDPR” posts/whitepapers, as they are often aimed at managers or legal people. Instead, I’ll focus on what GDPR means for developers.

Why am I qualified to do that? A few reasons – I was advisor to the deputy prime minister of a EU country, and because of that I’ve been both exposed and myself wrote some legislation. I’m familiar with the “legalese” and how the regulatory framework operates in general. I’m also a privacy advocate and I’ve been writing about GDPR-related stuff in the past, i.e. “before it was cool” (protecting sensitive data, the right to be forgotten). And finally, I’m currently working on a project that (among other things) aims to help with covering some GDPR aspects.

I’ll try to be a bit more comprehensive this time and cover as many aspects of the regulation that concern developers as I can. And while developers will mostly be concerned about how the systems they are working on have to change, it’s not unlikely that a less informed manager storms in in late spring, realizing GDPR is going to be in force tomorrow, asking “what should we do to get our system/website compliant”.

The rights of the user/client (referred to as “data subject” in the regulation) that I think are relevant for developers are: the right to erasure (the right to be forgotten/deleted from the system), right to restriction of processing (you still keep the data, but mark it as “restricted” and don’t touch it without further consent by the user), the right to data portability (the ability to export one’s data), the right to rectification (the ability to get personal data fixed), the right to be informed (getting human-readable information, rather than long terms and conditions), the right of access (the user should be able to see all the data you have about them), the right to data portability (the user should be able to get a machine-readable dump of their data).

Additionally, the relevant basic principles are: data minimization (one should not collect more data than necessary), integrity and confidentiality (all security measures to protect data that you can think of + measures to guarantee that the data has not been inappropriately modified).

Even further, the regulation requires certain processes to be in place within an organization (of more than 250 employees or if a significant amount of data is processed), and those include keeping a record of all types of processing activities carried out, including transfers to processors (3rd parties), which includes cloud service providers. None of the other requirements of the regulation have an exception depending on the organization size, so “I’m small, GDPR does not concern me” is a myth.

It is important to know what “personal data” is. Basically, it’s every piece of data that can be used to uniquely identify a person or data that is about an already identified person. It’s data that the user has explicitly provided, but also data that you have collected about them from either 3rd parties or based on their activities on the site (what they’ve been looking at, what they’ve purchased, etc.)

Having said that, I’ll list a number of features that will have to be implemented and some hints on how to do that, followed by some do’s and don’t’s.

  • “Forget me” – you should have a method that takes a userId and deletes all personal data about that user (in case they have been collected on the basis of consent, and not due to contract enforcement or legal obligation). It is actually useful for integration tests to have that feature (to cleanup after the test), but it may be hard to implement depending on the data model. In a regular data model, deleting a record may be easy, but some foreign keys may be violated. That means you have two options – either make sure you allow nullable foreign keys (for example an order usually has a reference to the user that made it, but when the user requests his data be deleted, you can set the userId to null), or make sure you delete all related data (e.g. via cascades). This may not be desirable, e.g. if the order is used to track available quantities or for accounting purposes. It’s a bit trickier for event-sourcing data models, or in extreme cases, ones that include some sort of blcokchain/hash chain/tamper-evident data structure. With event sourcing you should be able to remove a past event and re-generate intermediate snapshots. For blockchain-like structures – be careful what you put in there and avoid putting personal data of users. There is an option to use a chameleon hash function, but that’s suboptimal. Overall, you must constantly think of how you can delete the personal data. And “our data model doesn’t allow it” isn’t an excuse.
  • Notify 3rd parties for erasure – deleting things from your system may be one thing, but you are also obligated to inform all third parties that you have pushed that data to. So if you have sent personal data to, say, Salesforce, Hubspot, twitter, or any cloud service provider, you should call an API of theirs that allows for the deletion of personal data. If you are such a provider, obviously, your “forget me” endpoint should be exposed. Calling the 3rd party APIs to remove data is not the full story, though. You also have to make sure the information does not appear in search results. Now, that’s tricky, as Google doesn’t have an API for removal, only a manual process. Fortunately, it’s only about public profile pages that are crawlable by Google (and other search engines, okay…), but you still have to take measures. Ideally, you should make the personal data page return a 404 HTTP status, so that it can be removed.
  • Restrict processing – in your admin panel where there’s a list of users, there should be a button “restrict processing”. The user settings page should also have that button. When clicked (after reading the appropriate information), it should mark the profile as restricted. That means it should no longer be visible to the backoffice staff, or publicly. You can implement that with a simple “restricted” flag in the users table and a few if-clasues here and there.
  • Export data – there should be another button – “export data”. When clicked, the user should receive all the data that you hold about them. What exactly is that data – depends on the particular usecase. Usually it’s at least the data that you delete with the “forget me” functionality, but may include additional data (e.g. the orders the user has made may not be delete, but should be included in the dump). The structure of the dump is not strictly defined, but my recommendation would be to reuse schema.org definitions as much as possible, for either JSON or XML. If the data is simple enough, a CSV/XLS export would also be fine. Sometimes data export can take a long time, so the button can trigger a background process, which would then notify the user via email when his data is ready (twitter, for example, does that already – you can request all your tweets and you get them after a while).
  • Allow users to edit their profile – this seems an obvious rule, but it isn’t always followed. Users must be able to fix all data about them, including data that you have collected from other sources (e.g. using a “login with facebook” you may have fetched their name and address). Rule of thumb – all the fields in your “users” table should be editable via the UI. Technically, rectification can be done via a manual support process, but that’s normally more expensive for a business than just having the form to do it. There is one other scenario, however, when you’ve obtained the data from other sources (i.e. the user hasn’t provided their details to you directly). In that case there should still be a page where they can identify somehow (via email and/or sms confirmation) and get access to the data about them.
  • Consent checkboxes – this is in my opinion the biggest change that the regulation brings. “I accept the terms and conditions” would no longer be sufficient to claim that the user has given their consent for processing their data. So, for each particular processing activity there should be a separate checkbox on the registration (or user profile) screen. You should keep these consent checkboxes in separate columns in the database, and let the users withdraw their consent (by unchecking these checkboxes from their profile page – see the previous point). Ideally, these checkboxes should come directly from the register of processing activities (if you keep one). Note that the checkboxes should not be preselected, as this does not count as “consent”.
  • Re-request consent – if the consent users have given was not clear (e.g. if they simply agreed to terms & conditions), you’d have to re-obtain that consent. So prepare a functionality for mass-emailing your users to ask them to go to their profile page and check all the checkboxes for the personal data processing activities that you have.
  • “See all my data” – this is very similar to the “Export” button, except data should be displayed in the regular UI of the application rather than an XML/JSON format. For example, Google Maps shows you your location history – all the places that you’ve been to. It is a good implementation of the right to access. (Though Google is very far from perfect when privacy is concerned)
  • Age checks – you should ask for the user’s age, and if the user is a child (below 16), you should ask for parent permission. There’s no clear way how to do that, but my suggestion is to introduce a flow, where the child should specify the email of a parent, who can then confirm. Obviosuly, children will just cheat with their birthdate, or provide a fake parent email, but you will most likely have done your job according to the regulation (this is one of the “wishful thinking” aspects of the regulation).

Now some “do’s”, which are mostly about the technical measures needed to protect personal data. They may be more “ops” than “dev”, but often the application also has to be extended to support them. I’ve listed most of what I could think of in a previous post.

  • Encrypt the data in transit. That means that communication between your application layer and your database (or your message queue, or whatever component you have) should be over TLS. The certificates could be self-signed (and possibly pinned), or you could have an internal CA. Different databases have different configurations, just google “X encrypted connections. Some databases need gossiping among the nodes – that should also be configured to use encryption
  • Encrypt the data at rest – this again depends on the database (some offer table-level encryption), but can also be done on machine-level. E.g. using LUKS. The private key can be stored in your infrastructure, or in some cloud service like AWS KMS.
  • Encrypt your backups – kind of obvious
  • Implement pseudonymisation – the most obvious use-case is when you want to use production data for the test/staging servers. You should change the personal data to some “pseudonym”, so that the people cannot be identified. When you push data for machine learning purposes (to third parties or not), you can also do that. Technically, that could mean that your User object can have a “pseudonymize” method which applies hash+salt/bcrypt/PBKDF2 for some of the data that can be used to identify a person
  • Protect data integrity – this is a very broad thing, and could simply mean “have authentication mechanisms for modifying data”. But you can do something more, even as simple as a checksum, or a more complicated solution (like the one I’m working on). It depends on the stakes, on the way data is accessed, on the particular system, etc. The checksum can be in the form of a hash of all the data in a given database record, which should be updated each time the record is updated through the application. It isn’t a strong guarantee, but it is at least something.
  • Have your GDPR register of processing activities in something other than Excel – Article 30 says that you should keep a record of all the types of activities that you use personal data for. That sounds like bureaucracy, but it may be useful – you will be able to link certain aspects of your application with that register (e.g. the consent checkboxes, or your audit trail records). It wouldn’t take much time to implement a simple register, but the business requirements for that should come from whoever is responsible for the GDPR compliance. But you can advise them that having it in Excel won’t make it easy for you as a developer (imagine having to fetch the excel file internally, so that you can parse it and implement a feature). Such a register could be a microservice/small application deployed separately in your infrastructure.
  • Log access to personal data – every read operation on a personal data record should be logged, so that you know who accessed what and for what purpose
  • Register all API consumers – you shouldn’t allow anonymous API access to personal data. I’d say you should request the organization name and contact person for each API user upon registration, and add those to the data processing register. Note: some have treated article 30 as a requirement to keep an audit log. I don’t think it is saying that – instead it requires 250+ companies to keep a register of the types of processing activities (i.e. what you use the data for). There are other articles in the regulation that imply that keeping an audit log is a best practice (for protecting the integrity of the data as well as to make sure it hasn’t been processed without a valid reason)

Finally, some “don’t’s”.

  • Don’t use data for purposes that the user hasn’t agreed with – that’s supposed to be the spirit of the regulation. If you want to expose a new API to a new type of clients, or you want to use the data for some machine learning, or you decide to add ads to your site based on users’ behaviour, or sell your database to a 3rd party – think twice. I would imagine your register of processing activities could have a button to send notification emails to users to ask them for permission when a new processing activity is added (or if you use a 3rd party register, it should probably give you an API). So upon adding a new processing activity (and adding that to your register), mass email all users from whom you’d like consent.
  • Don’t log personal data – getting rid of the personal data from log files (especially if they are shipped to a 3rd party service) can be tedious or even impossible. So log just identifiers if needed. And make sure old logs files are cleaned up, just in case
  • Don’t put fields on the registration/profile form that you don’t need – it’s always tempting to just throw as many fields as the usability person/designer agrees on, but unless you absolutely need the data for delivering your service, you shouldn’t collect it. Names you should probably always collect, but unless you are delivering something, a home address or phone is unnecessary.
  • Don’t assume 3rd parties are compliant – you are responsible if there’s a data breach in one of the 3rd parties (e.g. “processors”) to which you send personal data. So before you send data via an API to another service, make sure they have at least a basic level of data protection. If they don’t, raise a flag with management.
  • Don’t assume having ISO XXX makes you compliant – information security standards and even personal data standards are a good start and they will probably 70% of what the regulation requires, but they are not sufficient – most of the things listed above are not covered in any of those standards

Overall, the purpose of the regulation is to make you take conscious decisions when processing personal data. It imposes best practices in a legal way. If you follow the above advice and design your data model, storage, data flow , API calls with data protection in mind, then you shouldn’t worry about the huge fines that the regulation prescribes – they are for extreme cases, like Equifax for example. Regulators (data protection authorities) will most likely have some checklists into which you’d have to somehow fit, but if you follow best practices, that shouldn’t be an issue.

I think all of the above features can be implemented in a few weeks by a small team. Be suspicious when a big vendor offers you a generic plug-and-play “GDPR compliance” solution. GDPR is not just about the technical aspects listed above – it does have organizational/process implications. But also be suspicious if a consultant claims GDPR is complicated. It’s not – it relies on a few basic principles that are in fact best practices anyway. Just don’t ignore them.

The post GDPR – A Practical Guide For Developers appeared first on Bozho's tech blog.

Object models

Post Syndicated from Eevee original https://eev.ee/blog/2017/11/28/object-models/

Anonymous asks, with dollars:

More about programming languages!

Well then!

I’ve written before about what I think objects are: state and behavior, which in practice mostly means method calls.

I suspect that the popular impression of what objects are, and also how they should work, comes from whatever C++ and Java happen to do. From that point of view, the whole post above is probably nonsense. If the baseline notion of “object” is a rigid definition woven tightly into the design of two massively popular languages, then it doesn’t even make sense to talk about what “object” should mean — it does mean the features of those languages, and cannot possibly mean anything else.

I think that’s a shame! It piles a lot of baggage onto a fairly simple idea. Polymorphism, for example, has nothing to do with objects — it’s an escape hatch for static type systems. Inheritance isn’t the only way to reuse code between objects, but it’s the easiest and fastest one, so it’s what we get. Frankly, it’s much closer to a speed tradeoff than a fundamental part of the concept.

We could do with more experimentation around how objects work, but that’s impossible in the languages most commonly thought of as object-oriented.

Here, then, is a (very) brief run through the inner workings of objects in four very dynamic languages. I don’t think I really appreciated objects until I’d spent some time with Python, and I hope this can help someone else whet their own appetite.

Python 3

Of the four languages I’m going to touch on, Python will look the most familiar to the Java and C++ crowd. For starters, it actually has a class construct.

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class Vector:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def __neg__(self):
        return Vector(-self.x, -self.y)

    def __div__(self, denom):
        return Vector(self.x / denom, self.y / denom)

    @property
    def magnitude(self):
        return (self.x ** 2 + self.y ** 2) ** 0.5

    def normalized(self):
        return self / self.magnitude

The __init__ method is an initializer, which is like a constructor but named differently (because the object already exists in a usable form by the time the initializer is called). Operator overloading is done by implementing methods with other special __dunder__ names. Properties can be created with @property, where the @ is syntax for applying a wrapper function to a function as it’s defined. You can do inheritance, even multiply:

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class Foo(A, B, C):
    def bar(self, x, y, z):
        # do some stuff
        super().bar(x, y, z)

Cool, a very traditional object model.

Except… for some details.

Some details

For one, Python objects don’t have a fixed layout. Code both inside and outside the class can add or remove whatever attributes they want from whatever object they want. The underlying storage is just a dict, Python’s mapping type. (Or, rather, something like one. Also, it’s possible to change, which will probably be the case for everything I say here.)

If you create some attributes at the class level, you’ll start to get a peek behind the curtains:

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class Foo:
    values = []

    def add_value(self, value):
        self.values.append(value)

a = Foo()
b = Foo()
a.add_value('a')
print(a.values)  # ['a']
b.add_value('b')
print(b.values)  # ['a', 'b']

The [] assigned to values isn’t a default assigned to each object. In fact, the individual objects don’t know about it at all! You can use vars(a) to get at the underlying storage dict, and you won’t see a values entry in there anywhere.

Instead, values lives on the class, which is a value (and thus an object) in its own right. When Python is asked for self.values, it checks to see if self has a values attribute; in this case, it doesn’t, so Python keeps going and asks the class for one.

Python’s object model is secretly prototypical — a class acts as a prototype, as a shared set of fallback values, for its objects.

In fact, this is also how method calls work! They aren’t syntactically special at all, which you can see by separating the attribute lookup from the call.

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print("abc".startswith("a"))  # True
meth = "abc".startswith
print(meth("a"))  # True

Reading obj.method looks for a method attribute; if there isn’t one on obj, Python checks the class. Here, it finds one: it’s a function from the class body.

Ah, but wait! In the code I just showed, meth seems to “know” the object it came from, so it can’t just be a plain function. If you inspect the resulting value, it claims to be a “bound method” or “built-in method” rather than a function, too. Something funny is going on here, and that funny something is the descriptor protocol.

Descriptors

Python allows attributes to implement their own custom behavior when read from or written to. Such an attribute is called a descriptor. I’ve written about them before, but here’s a quick overview.

If Python looks up an attribute, finds it in a class, and the value it gets has a __get__ method… then instead of using that value, Python will use the return value of its __get__ method.

The @property decorator works this way. The magnitude property in my original example was shorthand for doing this:

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class MagnitudeDescriptor:
    def __get__(self, instance, owner):
        if instance is None:
            return self
        return (instance.x ** 2 + instance.y ** 2) ** 0.5

class Vector:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    magnitude = MagnitudeDescriptor()

When you ask for somevec.magnitude, Python checks somevec but doesn’t find magnitude, so it consults the class instead. The class does have a magnitude, and it’s a value with a __get__ method, so Python calls that method and somevec.magnitude evaluates to its return value. (The instance is None check is because __get__ is called even if you get the descriptor directly from the class via Vector.magnitude. A descriptor intended to work on instances can’t do anything useful in that case, so the convention is to return the descriptor itself.)

You can also intercept attempts to write to or delete an attribute, and do absolutely whatever you want instead. But note that, similar to operating overloading in Python, the descriptor must be on a class; you can’t just slap one on an arbitrary object and have it work.

This brings me right around to how “bound methods” actually work. Functions are descriptors! The function type implements __get__, and when a function is retrieved from a class via an instance, that __get__ bundles the function and the instance together into a tiny bound method object. It’s essentially:

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class FunctionType:
    def __get__(self, instance, owner):
        if instance is None:
            return self
        return functools.partial(self, instance)

The self passed as the first argument to methods is not special or magical in any way. It’s built out of a few simple pieces that are also readily accessible to Python code.

Note also that because obj.method() is just an attribute lookup and a call, Python doesn’t actually care whether method is a method on the class or just some callable thing on the object. You won’t get the auto-self behavior if it’s on the object, but otherwise there’s no difference.

More attribute access, and the interesting part

Descriptors are one of several ways to customize attribute access. Classes can implement __getattr__ to intervene when an attribute isn’t found on an object; __setattr__ and __delattr__ to intervene when any attribute is set or deleted; and __getattribute__ to implement unconditional attribute access. (That last one is a fantastic way to create accidental recursion, since any attribute access you do within __getattribute__ will of course call __getattribute__ again.)

Here’s what I really love about Python. It might seem like a magical special case that descriptors only work on classes, but it really isn’t. You could implement exactly the same behavior yourself, in pure Python, using only the things I’ve just told you about. Classes are themselves objects, remember, and they are instances of type, so the reason descriptors only work on classes is that type effectively does this:

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class type:
    def __getattribute__(self, name):
        value = super().__getattribute__(name)
        # like all op overloads, __get__ must be on the type, not the instance
        ty = type(value)
        if hasattr(ty, '__get__'):
            # it's a descriptor!  this is a class access so there is no instance
            return ty.__get__(value, None, self)
        else:
            return value

You can even trivially prove to yourself that this is what’s going on by skipping over types behavior:

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class Descriptor:
    def __get__(self, instance, owner):
        print('called!')

class Foo:
    bar = Descriptor()

Foo.bar  # called!
type.__getattribute__(Foo, 'bar')  # called!
object.__getattribute__(Foo, 'bar')  # ...

And that’s not all! The mysterious super function, used to exhaustively traverse superclass method calls even in the face of diamond inheritance, can also be expressed in pure Python using these primitives. You could write your own superclass calling convention and use it exactly the same way as super.

This is one of the things I really like about Python. Very little of it is truly magical; virtually everything about the object model exists in the types rather than the language, which means virtually everything can be customized in pure Python.

Class creation and metaclasses

A very brief word on all of this stuff, since I could talk forever about Python and I have three other languages to get to.

The class block itself is fairly interesting. It looks like this:

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class Name(*bases, **kwargs):
    # code

I’ve said several times that classes are objects, and in fact the class block is one big pile of syntactic sugar for calling type(...) with some arguments to create a new type object.

The Python documentation has a remarkably detailed description of this process, but the gist is:

  • Python determines the type of the new class — the metaclass — by looking for a metaclass keyword argument. If there isn’t one, Python uses the “lowest” type among the provided base classes. (If you’re not doing anything special, that’ll just be type, since every class inherits from object and object is an instance of type.)

  • Python executes the class body. It gets its own local scope, and any assignments or method definitions go into that scope.

  • Python now calls type(name, bases, attrs, **kwargs). The name is whatever was right after class; the bases are position arguments; and attrs is the class body’s local scope. (This is how methods and other class attributes end up on the class.) The brand new type is then assigned to Name.

Of course, you can mess with most of this. You can implement __prepare__ on a metaclass, for example, to use a custom mapping as storage for the local scope — including any reads, which allows for some interesting shenanigans. The only part you can’t really implement in pure Python is the scoping bit, which has a couple extra rules that make sense for classes. (In particular, functions defined within a class block don’t close over the class body; that would be nonsense.)

Object creation

Finally, there’s what actually happens when you create an object — including a class, which remember is just an invocation of type(...).

Calling Foo(...) is implemented as, well, a call. Any type can implement calls with the __call__ special method, and you’ll find that type itself does so. It looks something like this:

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# oh, a fun wrinkle that's hard to express in pure python: type is a class, so
# it's an instance of itself
class type:
    def __call__(self, *args, **kwargs):
        # remember, here 'self' is a CLASS, an instance of type.
        # __new__ is a true constructor: object.__new__ allocates storage
        # for a new blank object
        instance = self.__new__(self, *args, **kwargs)
        # you can return whatever you want from __new__ (!), and __init__
        # is only called on it if it's of the right type
        if isinstance(instance, self):
            instance.__init__(*args, **kwargs)
        return instance

Again, you can trivially confirm this by asking any type for its __call__ method. Assuming that type doesn’t implement __call__ itself, you’ll get back a bound version of types implementation.

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>>> list.__call__
<method-wrapper '__call__' of type object at 0x7fafb831a400>

You can thus implement __call__ in your own metaclass to completely change how subclasses are created — including skipping the creation altogether, if you like.

And… there’s a bunch of stuff I haven’t even touched on.

The Python philosophy

Python offers something that, on the surface, looks like a “traditional” class/object model. Under the hood, it acts more like a prototypical system, where failed attribute lookups simply defer to a superclass or metaclass.

The language also goes to almost superhuman lengths to expose all of its moving parts. Even the prototypical behavior is an implementation of __getattribute__ somewhere, which you are free to completely replace in your own types. Proxying and delegation are easy.

Also very nice is that these features “bundle” well, by which I mean a library author can do all manner of convoluted hijinks, and a consumer of that library doesn’t have to see any of it or understand how it works. You only need to inherit from a particular class (which has a metaclass), or use some descriptor as a decorator, or even learn any new syntax.

This meshes well with Python culture, which is pretty big on the principle of least surprise. These super-advanced features tend to be tightly confined to single simple features (like “makes a weak attribute“) or cordoned with DSLs (e.g., defining a form/struct/database table with a class body). In particular, I’ve never seen a metaclass in the wild implement its own __call__.

I have mixed feelings about that. It’s probably a good thing overall that the Python world shows such restraint, but I wonder if there are some very interesting possibilities we’re missing out on. I implemented a metaclass __call__ myself, just once, in an entity/component system that strove to minimize fuss when communicating between components. It never saw the light of day, but I enjoyed seeing some new things Python could do with the same relatively simple syntax. I wouldn’t mind seeing, say, an object model based on composition (with no inheritance) built atop Python’s primitives.

Lua

Lua doesn’t have an object model. Instead, it gives you a handful of very small primitives for building your own object model. This is pretty typical of Lua — it’s a very powerful language, but has been carefully constructed to be very small at the same time. I’ve never encountered anything else quite like it, and “but it starts indexing at 1!” really doesn’t do it justice.

The best way to demonstrate how objects work in Lua is to build some from scratch. We need two key features. The first is metatables, which bear a passing resemblance to Python’s metaclasses.

Tables and metatables

The table is Lua’s mapping type and its primary data structure. Keys can be any value other than nil. Lists are implemented as tables whose keys are consecutive integers starting from 1. Nothing terribly surprising. The dot operator is sugar for indexing with a string key.

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local t = { a = 1, b = 2 }
print(t['a'])  -- 1
print(t.b)  -- 2
t.c = 3
print(t['c'])  -- 3

A metatable is a table that can be associated with another value (usually another table) to change its behavior. For example, operator overloading is implemented by assigning a function to a special key in a metatable.

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local t = { a = 1, b = 2 }
--print(t + 0)  -- error: attempt to perform arithmetic on a table value

local mt = {
    __add = function(left, right)
        return 12
    end,
}
setmetatable(t, mt)
print(t + 0)  -- 12

Now, the interesting part: one of the special keys is __index, which is consulted when the base table is indexed by a key it doesn’t contain. Here’s a table that claims every key maps to itself.

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local t = {}
local mt = {
    __index = function(table, key)
        return key
    end,
}
setmetatable(t, mt)
print(t.foo)  -- foo
print(t.bar)  -- bar
print(t[3])  -- 3

__index doesn’t have to be a function, either. It can be yet another table, in which case that table is simply indexed with the key. If the key still doesn’t exist and that table has a metatable with an __index, the process repeats.

With this, it’s easy to have several unrelated tables that act as a single table. Call the base table an object, fill the __index table with functions and call it a class, and you have half of an object system. You can even get prototypical inheritance by chaining __indexes together.

At this point things are a little confusing, since we have at least three tables going on, so here’s a diagram. Keep in mind that Lua doesn’t actually have anything called an “object”, “class”, or “method” — those are just convenient nicknames for a particular structure we might build with Lua’s primitives.

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                    ╔═══════════╗        ...
                    ║ metatable ║         ║
                    ╟───────────╢   ┌─────╨───────────────────────┐
                    ║ __index   ╫───┤ lookup table ("superclass") │
                    ╚═══╦═══════╝   ├─────────────────────────────┤
  ╔═══════════╗         ║           │ some other method           ┼─── function() ... end
  ║ metatable ║         ║           └─────────────────────────────┘
  ╟───────────╢   ┌─────╨──────────────────┐
  ║ __index   ╫───┤ lookup table ("class") │
  ╚═══╦═══════╝   ├────────────────────────┤
      ║           │ some method            ┼─── function() ... end
      ║           └────────────────────────┘
┌─────╨─────────────────┐
│ base table ("object") │
└───────────────────────┘

Note that a metatable is not the same as a class; it defines behavior, not methods. Conversely, if you try to use a class directly as a metatable, it will probably not do much. (This is pretty different from e.g. Python, where operator overloads are just methods with funny names. One nice thing about the Lua approach is that you can keep interface-like functionality separate from methods, and avoid clogging up arbitrary objects’ namespaces. You could even use a dummy table as a key and completely avoid name collisions.)

Anyway, code!

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local class = {
    foo = function(a)
        print("foo got", a)
    end,
}
local mt = { __index = class }
-- setmetatable returns its first argument, so this is nice shorthand
local obj1 = setmetatable({}, mt)
local obj2 = setmetatable({}, mt)
obj1.foo(7)  -- foo got 7
obj2.foo(9)  -- foo got 9

Wait, wait, hang on. Didn’t I call these methods? How do they get at the object? Maybe Lua has a magical this variable?

Methods, sort of

Not quite, but this is where the other key feature comes in: method-call syntax. It’s the lightest touch of sugar, just enough to have method invocation.

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-- note the colon!
a:b(c, d, ...)

-- exactly equivalent to this
-- (except that `a` is only evaluated once)
a.b(a, c, d, ...)

-- which of course is really this
a["b"](a, c, d, ...)

Now we can write methods that actually do something.

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local class = {
    bar = function(self)
        print("our score is", self.score)
    end,
}
local mt = { __index = class }
local obj1 = setmetatable({ score = 13 }, mt)
local obj2 = setmetatable({ score = 25 }, mt)
obj1:bar()  -- our score is 13
obj2:bar()  -- our score is 25

And that’s all you need. Much like Python, methods and data live in the same namespace, and Lua doesn’t care whether obj:method() finds a function on obj or gets one from the metatable’s __index. Unlike Python, the function will be passed self either way, because self comes from the use of : rather than from the lookup behavior.

(Aside: strictly speaking, any Lua value can have a metatable — and if you try to index a non-table, Lua will always consult the metatable’s __index. Strings all have the string library as a metatable, so you can call methods on them: try ("%s %s"):format(1, 2). I don’t think Lua lets user code set the metatable for non-tables, so this isn’t that interesting, but if you’re writing Lua bindings from C then you can wrap your pointers in metatables to give them methods implemented in C.)

Bringing it all together

Of course, writing all this stuff every time is a little tedious and error-prone, so instead you might want to wrap it all up inside a little function. No problem.

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local function make_object(body)
    -- create a metatable
    local mt = { __index = body }
    -- create a base table to serve as the object itself
    local obj = setmetatable({}, mt)
    -- and, done
    return obj
end

-- you can leave off parens if you're only passing in 
local Dog = {
    -- this acts as a "default" value; if obj.barks is missing, __index will
    -- kick in and find this value on the class.  but if obj.barks is assigned
    -- to, it'll go in the object and shadow the value here.
    barks = 0,

    bark = function(self)
        self.barks = self.barks + 1
        print("woof!")
    end,
}

local mydog = make_object(Dog)
mydog:bark()  -- woof!
mydog:bark()  -- woof!
mydog:bark()  -- woof!
print(mydog.barks)  -- 3
print(Dog.barks)  -- 0

It works, but it’s fairly barebones. The nice thing is that you can extend it pretty much however you want. I won’t reproduce an entire serious object system here — lord knows there are enough of them floating around — but the implementation I have for my LÖVE games lets me do this:

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local Animal = Object:extend{
    cries = 0,
}

-- called automatically by Object
function Animal:init()
    print("whoops i couldn't think of anything interesting to put here")
end

-- this is just nice syntax for adding a first argument called 'self', then
-- assigning this function to Animal.cry
function Animal:cry()
    self.cries = self.cries + 1
end

local Cat = Animal:extend{}

function Cat:cry()
    print("meow!")
    Cat.__super.cry(self)
end

local cat = Cat()
cat:cry()  -- meow!
cat:cry()  -- meow!
print(cat.cries)  -- 2

When I say you can extend it however you want, I mean that. I could’ve implemented Python (2)-style super(Cat, self):cry() syntax; I just never got around to it. I could even make it work with multiple inheritance if I really wanted to — or I could go the complete opposite direction and only implement composition. I could implement descriptors, customizing the behavior of individual table keys. I could add pretty decent syntax for composition/proxying. I am trying very hard to end this section now.

The Lua philosophy

Lua’s philosophy is to… not have a philosophy? It gives you the bare minimum to make objects work, and you can do absolutely whatever you want from there. Lua does have something resembling prototypical inheritance, but it’s not so much a first-class feature as an emergent property of some very simple tools. And since you can make __index be a function, you could avoid the prototypical behavior and do something different entirely.

The very severe downside, of course, is that you have to find or build your own object system — which can get pretty confusing very quickly, what with the multiple small moving parts. Third-party code may also have its own object system with subtly different behavior. (Though, in my experience, third-party code tries very hard to avoid needing an object system at all.)

It’s hard to say what the Lua “culture” is like, since Lua is an embedded language that’s often a little different in each environment. I imagine it has a thousand millicultures, instead. I can say that the tedium of building my own object model has led me into something very “traditional”, with prototypical inheritance and whatnot. It’s partly what I’m used to, but it’s also just really dang easy to get working.

Likewise, while I love properties in Python and use them all the dang time, I’ve yet to use a single one in Lua. They wouldn’t be particularly hard to add to my object model, but having to add them myself (or shop around for an object model with them and also port all my code to use it) adds a huge amount of friction. I’ve thought about designing an interesting ECS with custom object behavior, too, but… is it really worth the effort? For all the power and flexibility Lua offers, the cost is that by the time I have something working at all, I’m too exhausted to actually use any of it.

JavaScript

JavaScript is notable for being preposterously heavily used, yet not having a class block.

Well. Okay. Yes. It has one now. It didn’t for a very long time, and even the one it has now is sugar.

Here’s a vector class again:

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class Vector {
    constructor(x, y) {
        this.x = x;
        this.y = y;
    }

    get magnitude() {
        return Math.sqrt(this.x * this.x + this.y * this.y);
    }

    dot(other) {
        return this.x * other.x + this.y * other.y;
    }
}

In “classic” JavaScript, this would be written as:

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function Vector(x, y) {
    this.x = x;
    this.y = y;
}

Object.defineProperty(Vector.prototype, 'magnitude', {
    configurable: true,
    enumerable: true,
    get: function() {
        return Math.sqrt(this.x * this.x + this.y * this.y);
    },
});


Vector.prototype.dot = function(other) {
    return this.x * other.x + this.y * other.y;
};

Hm, yes. I can see why they added class.

The JavaScript model

In JavaScript, a new type is defined in terms of a function, which is its constructor.

Right away we get into trouble here. There is a very big difference between these two invocations, which I actually completely forgot about just now after spending four hours writing about Python and Lua:

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let vec = Vector(3, 4);
let vec = new Vector(3, 4);

The first calls the function Vector. It assigns some properties to this, which here is going to be window, so now you have a global x and y. It then returns nothing, so vec is undefined.

The second calls Vector with this set to a new empty object, then evaluates to that object. The result is what you’d actually expect.

(You can detect this situation with the strange new.target expression, but I have never once remembered to do so.)

From here, we have true, honest-to-god, first-class prototypical inheritance. The word “prototype” is even right there. When you write this:

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vec.dot(vec2)

JavaScript will look for dot on vec and (presumably) not find it. It then consults vecs prototype, an object you can see for yourself by using Object.getPrototypeOf(). Since vec is a Vector, its prototype is Vector.prototype.

I stress that Vector.prototype is not the prototype for Vector. It’s the prototype for instances of Vector.

(I say “instance”, but the true type of vec here is still just object. If you want to find Vector, it’s automatically assigned to the constructor property of its own prototype, so it’s available as vec.constructor.)

Of course, Vector.prototype can itself have a prototype, in which case the process would continue if dot were not found. A common (and, arguably, very bad) way to simulate single inheritance is to set Class.prototype to an instance of a superclass to get the prototype right, then tack on the methods for Class. Nowadays we can do Object.create(Superclass.prototype).

Now that I’ve been through Python and Lua, though, this isn’t particularly surprising. I kinda spoiled it.

I suppose one difference in JavaScript is that you can tack arbitrary attributes directly onto Vector all you like, and they will remain invisible to instances since they aren’t in the prototype chain. This is kind of backwards from Lua, where you can squirrel stuff away in the metatable.

Another difference is that every single object in JavaScript has a bunch of properties already tacked on — the ones in Object.prototype. Every object (and by “object” I mean any mapping) has a prototype, and that prototype defaults to Object.prototype, and it has a bunch of ancient junk like isPrototypeOf.

(Nit: it’s possible to explicitly create an object with no prototype via Object.create(null).)

Like Lua, and unlike Python, JavaScript doesn’t distinguish between keys found on an object and keys found via a prototype. Properties can be defined on prototypes with Object.defineProperty(), but that works just as well directly on an object, too. JavaScript doesn’t have a lot of operator overloading, but some things like Symbol.iterator also work on both objects and prototypes.

About this

You may, at this point, be wondering what this is. Unlike Lua and Python (and the last language below), this is a special built-in value — a context value, invisibly passed for every function call.

It’s determined by where the function came from. If the function was the result of an attribute lookup, then this is set to the object containing that attribute. Otherwise, this is set to the global object, window. (You can also set this to whatever you want via the call method on functions.)

This decision is made lexically, i.e. from the literal source code as written. There are no Python-style bound methods. In other words:

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// this = obj
obj.method()
// this = window
let meth = obj.method
meth()

Also, because this is reassigned on every function call, it cannot be meaningfully closed over, which makes using closures within methods incredibly annoying. The old approach was to assign this to some other regular name like self (which got syntax highlighting since it’s also a built-in name in browsers); then we got Function.bind, which produced a callable thing with a fixed context value, which was kind of nice; and now finally we have arrow functions, which explicitly close over the current this when they’re defined and don’t change it when called. Phew.

Class syntax

I already showed class syntax, and it’s really just one big macro for doing all the prototype stuff The Right Way. It even prevents you from calling the type without new. The underlying model is exactly the same, and you can inspect all the parts.

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class Vector { ... }

console.log(Vector.prototype);  // { dot: ..., magnitude: ..., ... }
let vec = new Vector(3, 4);
console.log(Object.getPrototypeOf(vec));  // same as Vector.prototype

// i don't know why you would subclass vector but let's roll with it
class Vectest extends Vector { ... }

console.log(Vectest.prototype);  // { ... }
console.log(Object.getPrototypeOf(Vectest.prototype))  // same as Vector.prototype

Alas, class syntax has a couple shortcomings. You can’t use the class block to assign arbitrary data to either the type object or the prototype — apparently it was deemed too confusing that mutations would be shared among instances. Which… is… how prototypes work. How Python works. How JavaScript itself, one of the most popular languages of all time, has worked for twenty-two years. Argh.

You can still do whatever assignment you want outside of the class block, of course. It’s just a little ugly, and not something I’d think to look for with a sugary class.

A more subtle result of this behavior is that a class block isn’t quite the same syntax as an object literal. The check for data isn’t a runtime thing; class Foo { x: 3 } fails to parse. So JavaScript now has two largely but not entirely identical styles of key/value block.

Attribute access

Here’s where things start to come apart at the seams, just a little bit.

JavaScript doesn’t really have an attribute protocol. Instead, it has two… extension points, I suppose.

One is Object.defineProperty, seen above. For common cases, there’s also the get syntax inside a property literal, which does the same thing. But unlike Python’s @property, these aren’t wrappers around some simple primitives; they are the primitives. JavaScript is the only language of these four to have “property that runs code on access” as a completely separate first-class concept.

If you want to intercept arbitrary attribute access (and some kinds of operators), there’s a completely different primitive: the Proxy type. It doesn’t let you intercept attribute access or operators; instead, it produces a wrapper object that supports interception and defers to the wrapped object by default.

It’s cool to see composition used in this way, but also, extremely weird. If you want to make your own type that overloads in or calling, you have to return a Proxy that wraps your own type, rather than actually returning your own type. And (unlike the other three languages in this post) you can’t return a different type from a constructor, so you have to throw that away and produce objects only from a factory. And instanceof would be broken, but you can at least fix that with Symbol.hasInstance — which is really operator overloading, implement yet another completely different way.

I know the design here is a result of legacy and speed — if any object could intercept all attribute access, then all attribute access would be slowed down everywhere. Fair enough. It still leaves the surface area of the language a bit… bumpy?

The JavaScript philosophy

It’s a little hard to tell. The original idea of prototypes was interesting, but it was hidden behind some very awkward syntax. Since then, we’ve gotten a bunch of extra features awkwardly bolted on to reflect the wildly varied things the built-in types and DOM API were already doing. We have class syntax, but it’s been explicitly designed to avoid exposing the prototype parts of the model.

I admit I don’t do a lot of heavy JavaScript, so I might just be overlooking it, but I’ve seen virtually no code that makes use of any of the recent advances in object capabilities. Forget about custom iterators or overloading call; I can’t remember seeing any JavaScript in the wild that even uses properties yet. I don’t know if everyone’s waiting for sufficient browser support, nobody knows about them, or nobody cares.

The model has advanced recently, but I suspect JavaScript is still shackled to its legacy of “something about prototypes, I don’t really get it, just copy the other code that’s there” as an object model. Alas! Prototypes are so good. Hopefully class syntax will make it a bit more accessible, as it has in Python.

Perl 5

Perl 5 also doesn’t have an object system and expects you to build your own. But where Lua gives you two simple, powerful tools for building one, Perl 5 feels more like a puzzle with half the pieces missing. Clearly they were going for something, but they only gave you half of it.

In brief, a Perl object is a reference that has been blessed with a package.

I need to explain a few things. Honestly, one of the biggest problems with the original Perl object setup was how many strange corners and unique jargon you had to understand just to get off the ground.

(If you want to try running any of this code, you should stick a use v5.26; as the first line. Perl is very big on backwards compatibility, so you need to opt into breaking changes, and even the mundane say builtin is behind a feature gate.)

References

A reference in Perl is sort of like a pointer, but its main use is very different. See, Perl has the strange property that its data structures try very hard to spill their contents all over the place. Despite having dedicated syntax for arrays — @foo is an array variable, distinct from the single scalar variable $foo — it’s actually impossible to nest arrays.

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my @foo = (1, 2, 3, 4);
my @bar = (@foo, @foo);
# @bar is now a flat list of eight items: 1, 2, 3, 4, 1, 2, 3, 4

The idea, I guess, is that an array is not one thing. It’s not a container, which happens to hold multiple things; it is multiple things. Anywhere that expects a single value, such as an array element, cannot contain an array, because an array fundamentally is not a single value.

And so we have “references”, which are a form of indirection, but also have the nice property that they’re single values. They add containment around arrays, and in general they make working with most of Perl’s primitive types much more sensible. A reference to a variable can be taken with the \ operator, or you can use [ ... ] and { ... } to directly create references to anonymous arrays or hashes.

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my @foo = (1, 2, 3, 4);
my @bar = (\@foo, \@foo);
# @bar is now a nested list of two items: [1, 2, 3, 4], [1, 2, 3, 4]

(Incidentally, this is the sole reason I initially abandoned Perl for Python. Non-trivial software kinda requires nesting a lot of data structures, so you end up with references everywhere, and the syntax for going back and forth between a reference and its contents is tedious and ugly.)

A Perl object must be a reference. Perl doesn’t care what kind of reference — it’s usually a hash reference, since hashes are a convenient place to store arbitrary properties, but it could just as well be a reference to an array, a scalar, or even a sub (i.e. function) or filehandle.

I’m getting a little ahead of myself. First, the other half: blessing and packages.

Packages and blessing

Perl packages are just namespaces. A package looks like this:

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package Foo::Bar;

sub quux {
    say "hi from quux!";
}

# now Foo::Bar::quux() can be called from anywhere

Nothing shocking, right? It’s just a named container. A lot of the details are kind of weird, like how a package exists in some liminal quasi-value space, but the basic idea is a Bag Of Stuff.

The final piece is “blessing,” which is Perl’s funny name for binding a package to a reference. A very basic class might look like this:

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package Vector;

# the name 'new' is convention, not special
sub new {
    # perl argument passing is weird, don't ask
    my ($class, $x, $y) = @_;

    # create the object itself -- here, unusually, an array reference makes sense
    my $self = [ $x, $y ];

    # associate the package with that reference
    # note that $class here is just the regular string, 'Vector'
    bless $self, $class;

    return $self;
}

sub x {
    my ($self) = @_;
    return $self->[0];
}

sub y {
    my ($self) = @_;
    return $self->[1];
}

sub magnitude {
    my ($self) = @_;
    return sqrt($self->x ** 2 + $self->y ** 2);
}

# switch back to the "default" package
package main;

# -> is method call syntax, which passes the invocant as the first argument;
# for a package, that's just the package name
my $vec = Vector->new(3, 4);
say $vec->magnitude;  # 5

A few things of note here. First, $self->[0] has nothing to do with objects; it’s normal syntax for getting the value of a index 0 out of an array reference called $self. (Most classes are based on hashrefs and would use $self->{value} instead.) A blessed reference is still a reference and can be treated like one.

In general, -> is Perl’s dereferencey operator, but its exact behavior depends on what follows. If it’s followed by brackets, then it’ll apply the brackets to the thing in the reference: ->{} to index a hash reference, ->[] to index an array reference, and ->() to call a function reference.

But if -> is followed by an identifier, then it’s a method call. For packages, that means calling a function in the package and passing the package name as the first argument. For objects — blessed references — that means calling a function in the associated package and passing the object as the first argument.

This is a little weird! A blessed reference is a superposition of two things: its normal reference behavior, and some completely orthogonal object behavior. Also, object behavior has no notion of methods vs data; it only knows about methods. Perl lets you omit parentheses in a lot of places, including when calling a method with no arguments, so $vec->magnitude is really $vec->magnitude().

Perl’s blessing bears some similarities to Lua’s metatables, but ultimately Perl is much closer to Ruby’s “message passing” approach than the above three languages’ approaches of “get me something and maybe it’ll be callable”. (But this is no surprise — Ruby is a spiritual successor to Perl 5.)

All of this leads to one little wrinkle: how do you actually expose data? Above, I had to write x and y methods. Am I supposed to do that for every single attribute on my type?

Yes! But don’t worry, there are third-party modules to help with this incredibly fundamental task. Take Class::Accessor::Fast, so named because it’s faster than Class::Accessor:

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package Foo;
use base qw(Class::Accessor::Fast);
__PACKAGE__->mk_accessors(qw(fred wilma barney));

(__PACKAGE__ is the lexical name of the current package; qw(...) is a list literal that splits its contents on whitespace.)

This assumes you’re using a hashref with keys of the same names as the attributes. $obj->fred will return the fred key from your hashref, and $obj->fred(4) will change it to 4.

You also, somewhat bizarrely, have to inherit from Class::Accessor::Fast. Speaking of which,

Inheritance

Inheritance is done by populating the package-global @ISA array with some number of (string) names of parent packages. Most code instead opts to write use base ...;, which does the same thing. Or, more commonly, use parent ...;, which… also… does the same thing.

Every package implicitly inherits from UNIVERSAL, which can be freely modified by Perl code.

A method can call its superclass method with the SUPER:: pseudo-package:

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sub foo {
    my ($self) = @_;
    $self->SUPER::foo;
}

However, this does a depth-first search, which means it almost certainly does the wrong thing when faced with multiple inheritance. For a while the accepted solution involved a third-party module, but Perl eventually grew an alternative you have to opt into: C3, which may be more familiar to you as the order Python uses.

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use mro 'c3';

sub foo {
    my ($self) = @_;
    $self->next::method;
}

Offhand, I’m not actually sure how next::method works, seeing as it was originally implemented in pure Perl code. I suspect it involves peeking at the caller’s stack frame. If so, then this is a very different style of customizability from e.g. Python — the MRO was never intended to be pluggable, and the use of a special pseudo-package means it isn’t really, but someone was determined enough to make it happen anyway.

Operator overloading and whatnot

Operator overloading looks a little weird, though really it’s pretty standard Perl.

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package MyClass;

use overload '+' => \&_add;

sub _add {
    my ($self, $other, $swap) = @_;
    ...
}

use overload here is a pragma, where “pragma” means “regular-ass module that does some wizardry when imported”.

\&_add is how you get a reference to the _add sub so you can pass it to the overload module. If you just said &_add or _add, that would call it.

And that’s it; you just pass a map of operators to functions to this built-in module. No worry about name clashes or pollution, which is pretty nice. You don’t even have to give references to functions that live in the package, if you don’t want them to clog your namespace; you could put them in another package, or even inline them anonymously.

One especially interesting thing is that Perl lets you overload every operator. Perl has a lot of operators. It considers some math builtins like sqrt and trig functions to be operators, or at least operator-y enough that you can overload them. You can also overload the “file text” operators, such as -e $path to test whether a file exists. You can overload conversions, including implicit conversion to a regex. And most fascinating to me, you can overload dereferencing — that is, the thing Perl does when you say $hashref->{key} to get at the underlying hash. So a single object could pretend to be references of multiple different types, including a subref to implement callability. Neat.

Somewhat related: you can overload basic operators (indexing, etc.) on basic types (not references!) with the tie function, which is designed completely differently and looks for methods with fixed names. Go figure.

You can intercept calls to nonexistent methods by implementing a function called AUTOLOAD, within which the $AUTOLOAD global will contain the name of the method being called. Originally this feature was, I think, intended for loading binary components or large libraries on-the-fly only when needed, hence the name. Offhand I’m not sure I ever saw it used the way __getattr__ is used in Python.

Is there a way to intercept all method calls? I don’t think so, but it is Perl, so I must be forgetting something.

Actually no one does this any more

Like a decade ago, a council of elder sages sat down and put together a whole whizbang system that covers all of it: Moose.

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package Vector;
use Moose;

has x => (is => 'rw', isa => 'Int');
has y => (is => 'rw', isa => 'Int');

sub magnitude {
    my ($self) = @_;
    return sqrt($self->x ** 2 + $self->y ** 2);
}

Moose has its own way to do pretty much everything, and it’s all built on the same primitives. Moose also adds metaclasses, somehow, despite that the underlying model doesn’t actually support them? I’m not entirely sure how they managed that, but I do remember doing some class introspection with Moose and it was much nicer than the built-in way.

(If you’re wondering, the built-in way begins with looking at the hash called %Vector::. No, that’s not a typo.)

I really cannot stress enough just how much stuff Moose does, but I don’t want to delve into it here since Moose itself is not actually the language model.

The Perl philosophy

I hope you can see what I meant with what I first said about Perl, now. It has multiple inheritance with an MRO, but uses the wrong one by default. It has extensive operator overloading, which looks nothing like how inheritance works, and also some of it uses a totally different mechanism with special method names instead. It only understands methods, not data, leaving you to figure out accessors by hand.

There’s 70% of an object system here with a clear general design it was gunning for, but none of the pieces really look anything like each other. It’s weird, in a distinctly Perl way.

The result is certainly flexible, at least! It’s especially cool that you can use whatever kind of reference you want for storage, though even as I say that, I acknowledge it’s no different from simply subclassing list or something in Python. It feels different in Perl, but maybe only because it looks so different.

I haven’t written much Perl in a long time, so I don’t know what the community is like any more. Moose was already ubiquitous when I left, which you’d think would let me say “the community mostly focuses on the stuff Moose can do” — but even a decade ago, Moose could already do far more than I had ever seen done by hand in Perl. It’s always made a big deal out of roles (read: interfaces), for instance, despite that I’d never seen anyone care about them in Perl before Moose came along. Maybe their presence in Moose has made them more popular? Who knows.

Also, I wrote Perl seriously, but in the intervening years I’ve only encountered people who only ever used Perl for one-offs. Maybe it’ll come as a surprise to a lot of readers that Perl has an object model at all.

End

Well, that was fun! I hope any of that made sense.

Special mention goes to Rust, which doesn’t have an object model you can fiddle with at runtime, but does do things a little differently.

It’s been really interesting thinking about how tiny differences make a huge impact on what people do in practice. Take the choice of storage in Perl versus Python. Perl’s massively common URI class uses a string as the storage, nothing else; I haven’t seen anything like that in Python aside from markupsafe, which is specifically designed as a string type. I would guess this is partly because Perl makes you choose — using a hashref is an obvious default, but you have to make that choice one way or the other. In Python (especially 3), inheriting from object and getting dict-based storage is the obvious thing to do; the ability to use another type isn’t quite so obvious, and doing it “right” involves a tiny bit of extra work.

Or, consider that Lua could have descriptors, but the extra bit of work (especially design work) has been enough of an impediment that I’ve never implemented them. I don’t think the object implementations I’ve looked at have included them, either. Super weird!

In that light, it’s only natural that objects would be so strongly associated with the features Java and C++ attach to them. I think that makes it all the more important to play around! Look at what Moose has done. No, really, you should bear in mind my description of how Perl does stuff and flip through the Moose documentation. It’s amazing what they’ve built.