after PEP 570, there is a syntax to specify positional-only parameters in the function definition. Unfortunately, most stdlib modules ignore this (the os module seems to be an exception). The math module is an example. While

>>> inspect.signature(math.ceil)
<Signature (x, /)>

the module docs display the function signature as math.ceil(x), that is wrong:

>>> math.ceil(x=3.14)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: math.ceil() takes no keyword arguments

Linked PRs

• gh-101118: correct function signatures in the math module docs #101120