Fix is_simple_callable with variable args, kwargs

[rpkilby]

Fix #4602

py3k is_simple_callable was not accounting for variable args and kwargs

[tomchristie]

Thanks for working towards this! Milestoned this as 3.5.2 to keep it on our immediate horizon. Some tests failing in its current state.

[rpkilby]

yep - see my comment on #4602. I'll have to think more on how to proceed with the fix.

[rpkilby]

This should be good to go now. There were two separate issues:

• The callable check was incorrect - needed to be the more restrictive isfunction or ismethod.
• The parameter check needed to allow for *args and **kwargs. This is necessary to validate get_FIELD_display() as it's a curried function where it's only inspectable parameters are *args and **kwargs.

[tomchristie]

Great work!

😄 👍 ✨

[carltongibson]

@rpkilby: Can you just explain this call to me, just for my sanity? 🙂

I'm expecting any(iterable) — it looks like bool or bool or generator, so why isn't it this:

>>> a = True
>>> b = True
>>> def c():
...     yield True
...     yield False
>>> all(a or b or c())
TypeError: 'bool' object is not iterable

Sorry for being slow. Thanks!

[carltongibson]

OK. 1 second after Comment it becomes clear. ... — even seeing it though, I still struggle to read it right...

[rpkilby]

@carltongibson - it probably wouldn't have hurt to have added a second set of parens wrapping the conditions

return all((
        param.kind == param.VAR_POSITIONAL or
        param.kind == param.VAR_KEYWORD or
        param.default != param.empty
    ) for param in params
)

[carltongibson]

Yeah, that's kind to of where I came to. (That vs a nested any)

It's fine.