Fixing an error message in the AbstractMethodError class found in pandas/errors/init.py.
Currently:
raise ValueError(
f"methodtype must be one of {methodtype}, got {types} instead."
)
Here, {methodtype} and {types} are swapped.
This means if you called this error with methodtype="foo", the message would read:
methodtype must be one of foo, got {'method', 'classmethod', 'staticmethod', 'property'} instead.

That’s confusing, because the set of valid types should be listed after “must be one of”, and the invalid value you passed should be listed after “got”.

Corrected:

raise ValueError(
f"methodtype must be one of {types}, got {methodtype} instead."
)
Now, if you called this error with methodtype="foo", the message would read:
methodtype must be one of {'method', 'classmethod', 'staticmethod', 'property'}, got foo instead.

This is clearer and follows standard error message conventions.