.arguments property ignores keyword-only args, *args, and **kwargs

[jacobtylerwalls]

>>> from astroid import extract_node
>>> node = extract_node("""def a(*args, b=None, c=None, **kwargs): ...""")
>>> node.args.arguments
[]

Expected to find all the arguments from the function signature.

The wanted data can be found here:

>>> node.args.vararg
'args'
>>> node.args.kwarg
'kwargs'
>>> node.args.kwonlyargs
[<AssignName.b l.1 at 0x1048189b0>, <AssignName.c l.1 at 0x104818830>]

Discussed at pylint-dev/pylint#7577 (comment).

Notice that positional-only args are found for some reason 🤷

[crazybolillo]

Should the definition be changed as well? It states args.arguments returns required arguments, and AFAIK in the example none are required (I can call a without supplying any arguments).

I tried running the following:

>>> node = extract_node("""def a(kiwi, apple, *args, b=None, c=None, **kwargs): ...""")
>>> node.args.arguments
[<AssignName.kiwi l.1 at 0x7f5c55986b90>, <AssignName.apple l.1 at 0x7f5c55985a50>]

And it seems correct to me 🤔

[DanielNoord]

astroid/astroid/nodes/node_classes.py

Lines 685 to 688 in fef38f2

	@cached_property
	def arguments(self):
	"""Get all the arguments for this node, including positional only and positional and keyword"""
	return list(itertools.chain((self.posonlyargs or ()), self.args or ()))

The docstring seems to be correct?

[jacobtylerwalls]

Depends on how you parse the language. "positional and keyword" could describe the argument kiwi and exclude keyword-only arguments.

Essentially, the crux of this is whether we should

• leave the function as is, and audit everywhere that uses it (given that we keep finding bugs)
• change the function

@crazybolillo have you happened to sample the places that use this function to be able to offer a view on that? I'd be eager to hear it!

[crazybolillo]

I think I got confused about the documentation 😭. I was reading the docstring for args (node.args.args in the example):

astroid/astroid/nodes/node_classes.py

Lines 554 to 555 in d4f4452

	args: list[AssignName] | None
	"""The names of the required arguments.

but we are dealing with arguments (node.args.arguments). I will review the code further to see if I can come up with something

[Pierre-Sassoulas]

I also misunderstood the documentation or it's wrong and #2240 is the fix.