Bug report

The behavior ofpartialmethod changed in python3.11. This caused a library that I usetestsuite to fail.

Here is a minimal use case that demonstrates this:

from functools import partialmethodclass Cell:    def __init__(self):        self.alive = False    def set_state(self, state):        self.alive = bool(state)class Wrapper:    def set_state_wrap(self, cell: Cell, state):        cell.set_state(state)wrapper = Wrapper()Cell.set_alive = partialmethod(wrapper.set_state_wrap, True)cell = Cell()cell.set_alive()print(cell.alive)

In python3.10, this printsTrue. In python3.11 it errors with:

Traceback (most recent call last):  File "/home/gary/partialmethod.py", line 23, in <module>    c.set_alive()TypeError: Wrapper.set_state_wrap() missing 1 required positional argument: 'state'

The arguments passed toWrapper.set_state_wrap are:
python3.10:wrapper, cell, True
python3.11:cell, True

Sopartialmethod is forgetting thatset_state_wrap is a method ofwrapper, and it needs to pass that in as the first arg.

I know that the way that they are usingpartialmethod here is not how it is intended to be used, and feels wrong. However this change is behavior if intended should be documented.

Your environment

• CPython versions tested on: Python 3.11.0 (broken) Python 3.10.7 (working)
• Operating system and architecture: Fedora Linux 36