add missing kwargs from Enum functional api signature

[anentropic]

I'm making an attempt to address python/mypy#4184

from enum import Enum

# Error: Too many arguments for Enum()
PictureSize = Enum('PictureSize', 'P0 P1 P2 P3 P4 P5 P6 P7 P8', type=str, module=__name__)

to really support the type arg fully I think needs python/typing#213 ... then with the overloads decorator (since arg is optional) we could express that the return type is a subclass i.e. -> Type[Intersection[_T, _T2]]

but at the moment it's just kind of annotated and ignored

[JelleZijlstra]

I don't think this is right—this method is for constructing enum instances, not enum classes. If anything, your change should be on EnumMeta.

[JelleZijlstra]

So maybe we can't actually do much to fix this in typeshed.

[anentropic]

I must admit I find the Enum class rather baffling, I will look more into it

[anentropic]

@JelleZijlstra

Looking into the Python source code for Enum I could see that these args actually belong on EnumMeta.__call__

I have added them there, however if I run mypy on my problem enum example with this modified typeshed I get:

.../typeshed/stdlib/3.4/enum.pyi:16: error: Signature of "__call__" incompatible with supertype "type"

but the signature of class type in typeshed builtins.py is

def __call__(self, *args: Any, **kwds: Any) -> Any: ...

so it seems like the signature of __call__ is not the cause of my original problem.

I guess as you say it's not fixable in typeshed and needs some magic in mypy to understand that Enum(...) does not instantiate an Enum, due to the wacky metaclass tricks being employed here.

[JelleZijlstra]

Yes, so let's close this and attempt to fix the issue in mypy instead.