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On Thu, 2 Dec 2021 at 08:29, Paul Moore <p.f.moore@gmail.com> wrote:
On Wed, 1 Dec 2021 at 22:27, Greg Ewing <greg.ewing@canterbury.ac.nz> wrote:
On 2/12/21 4:40 am, Paul Moore wrote:
the intended use is that people must supply a list[int] or not supply the argument *at all*.
I don't think this is a style of API that we should be encouraging people to create, because it results in things that are very awkward to wrap.
Hmm, interesting point, I agree with you. It's particularly telling that I got sucked into designing that sort of API, even though I know it's got this problem. I guess that counts as an argument against the late bound defaults proposal - or maybe even two:
1. It's hard (if not impossible) to wrap functions that use late-bound defaults. 2. The feature encourages people to write such unwrappable functions when an alternative formulation that is wrappable is just as good.
(That may actually only be one point - obviously a feature encourages people to use it, and any feature can be over-used. But the point about wrappability stands).
Actually, Chris - does functools.wraps work properly in your implementation when wrapping functions with late-bound defaults?
def dec(f): ... @wraps(f) ... def inner(*args, **kw): ... print("Calling") ... return f(*args, **kw) ... return inner ... @dec ... def g(a => []): ... return len(a)
Paul