tkinter: Simplify wm_iconphoto()

[Akuli]

The whole method is just weird. The default argument is a boolean cannot be passed as a keyword argument:

>>> import tkinter
>>> root = tkinter.Tk()
>>> root.wm_iconphoto('lol', default=True)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: Wm.wm_iconphoto() got multiple values for argument 'default'

Also, the default argument must be given. So calling this method looks like window.wm_iconphoto(False, some_image) or window.wm_iconphoto(False, image1, image2, image3).

Having a required positional-only boolean parameter is dumb, but tkinter does it, and it can't be changed without breaking backwards compatibility.

See also the discussion in #11506.

[AlexWaygood]

Thanks!

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉

[AlexWaygood]

We should do the same thing for os.execl and os.execlp, which were changed in #11505. file is pos-or-keyword according to inspect.signature, so we'll need to add a stubtest allowlist. But you can't actually pass it as a keyword parameter, same as for wm_iconphoto:

>>> import os
>>> os.execl(file='foo')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<frozen os>", line 548, in execl
ValueError: execv() arg 2 must not be empty
>>> os.execl('bar', file='foo')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: execl() got multiple values for argument 'file'

[AlexWaygood]

We should do the same thing for os.execl and os.execlp, which were changed in #11505. file is pos-or-keyword according to inspect.signature, so we'll need to add a stubtest allowlist. But you can't actually pass it as a keyword parameter, same as for wm_iconphoto:

>>> import os
>>> os.execl(file='foo')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<frozen os>", line 548, in execl
ValueError: execv() arg 2 must not be empty
>>> os.execl('bar', file='foo')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: execl() got multiple values for argument 'file'

Cc. @sobolevn

[sobolevn]

I think the proper solution is to use *args: Unpack, actually. It is harder to read, but at the same time it is more correct semantically: our goal is to specify the *args structure and Unpack does just that. But, it is a bit of a mess, I agree :(

[AlexWaygood]

I think the proper solution is to use *args: Unpack, actually. It is harder to read, but at the same time it is more correct semantically: our goal is to specify the *args structure and Unpack does just that. But, it is a bit of a mess, I agree :(

The current signature after #11505 specifies that file can be passed as a keyword argument to those os functions. Look at the REPL snippet I posted above: it cannot be passed as a keyword argument, or you get a runtime error.

[sobolevn]

@AlexWaygood mypy correctly handles this case: https://mypy-play.net/?mypy=latest&python=3.12&gist=6133cabb92b165e44e240d341383fe31

It is a general rule: you cannot pass keyword args if you also pass *args args.

[AlexWaygood]

@AlexWaygood mypy correctly handles this case: https://mypy-play.net/?mypy=latest&python=3.12&gist=6133cabb92b165e44e240d341383fe31

It is a general rule: you cannot pass keyword args if you also pass *args args.

Hmm, fair enough. I still feel like the signature for the os functions is now unnecessarily ugly though, which isn't great for users of IDEs, who'll now have to decipher Unpack in autocomplete suggestions etc

[sobolevn]

I always forget about IDE users, since I don't use one :)