Open
Description
Please consider
from functools import singledispatch
import typing as tp
@singledispatch
def f(x: tp.Any) -> None: pass
@f.register
def _f_list(x: list[int]) -> None: pass
if __name__ == '__main__':
f([1, 2, 3])
Then
$ mypy sp.py
Success: no issues found in 1 source file
# on import no error as well, so Mypy raising an error would be very useful
$ python -c 'import sp'
On runtime
$ python sp.py
Traceback (most recent call last):
File "/usr/lib/python3.10/functools.py", line 831, in dispatch
impl = dispatch_cache[cls]
File "/usr/lib/python3.10/weakref.py", line 416, in __getitem__
return self.data[ref(key)]
KeyError: <weakref at 0x7f390d605c60; to 'type' at 0x7f390e07bd00 (list)>
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/lib/python3.10/functools.py", line 834, in dispatch
impl = registry[cls]
KeyError: <class 'list'>
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/home/wrobell/projects/rbfly/sp.py", line 11, in <module>
f([1, 2, 3])
File "/usr/lib/python3.10/functools.py", line 878, in wrapper
return dispatch(args[0].__class__)(*args, **kw)
File "/usr/lib/python3.10/functools.py", line 836, in dispatch
impl = _find_impl(cls, registry)
File "/usr/lib/python3.10/functools.py", line 783, in _find_impl
mro = _compose_mro(cls, registry.keys())
File "/usr/lib/python3.10/functools.py", line 744, in _compose_mro
types = [n for n in types if is_related(n)]
File "/usr/lib/python3.10/functools.py", line 744, in <listcomp>
types = [n for n in types if is_related(n)]
File "/usr/lib/python3.10/functools.py", line 743, in is_related
and issubclass(cls, typ))
TypeError: issubclass() argument 2 cannot be a parameterized generic
Some context (in general we need to be better at distinguishing between Python types and annotation types)