Post Syndicated from original https://lwn.net/Articles/904900/

Discussion on PEP 671 (“Syntax
for late-bound function argument defaults”) has been going on—in fits and
starts—since it was introduced last
October. The idea is to provide a way
to specify the default for a function argument that is evaluated in the
scope of the function
call, which will allow more concise, and visible, defaults. But there has
been a persistent complaint that what the
language needs is a more-general
deferred computation feature; late-bound defaults would simply fall out as
one specific user of the feature. The arrival of a proposal for deferred
computation did not really
accomplish that goal, however.