@singledispatchmethod fails mypy validation #3898
Description
I am trying to validate the following example straight from the docs -- Here I renamed the two methods _ from the example to _int and _bool to obviate an issue already reported, i.e., python/mypy#2904
from functools import singledispatchmethod
class Negator:
@singledispatchmethod
def neg(self, arg):
raise NotImplementedError("Cannot negate a")
@neg.register
def _int(self, arg: int):
return -arg
@neg.register
def _bool(self, arg: bool):
return not arg
n = Negator()
n.neg(2)
n.neg(True)When I run mypy checks on this file, I get the following errors:
negator.py:17: error: "singledispatchmethod[Any]" not callable negator.py:18: error: "singledispatchmethod[Any]" not callable Found 2 errors in 1 file (checked 1 source file)
Python 3.8.2
mypy 0.770
Activity
functools.singledispatchmethod: add __call__ for better results
hauntsaninja commented on Apr 2, 2020
Thanks for the report! Linked PR fixes your repro for me locally.
functools.singledispatchmethod: add __call__ for better results (#3899)