Check for Match instance in Union[Match, str] #2282
Description
It's not clear for me, how should I use Pattern and Match type aliases to pick apart Union[Match, str].
It looks like Match type alias supports __subclasscheck__, but mypy used with
from typing import Match, Union
def process_consumed_issubclass(consumed: Union[Match, str]) -> str:
if issubclass(type(consumed), Match):
return consumed.group('res')
return consumed
returns
test_mypy_match.py: note: In function "process_consumed_issubclass":
test_mypy_match.py:7: error: Some element of union has no attribute "group"
test_mypy_match.py:9: error: Incompatible return value type (got "Union[Match[Any], str]", expected "str")
Match.impl_type have type(stdlib_re.match('', '')), but isinstance check still doesn't work
def process_consumed_isinstance(consumed: Union[Match, str]) -> str:
if isinstance(consumed, Match.impl_type):
return consumed.group('res')
return consumed
test_mypy_match.py: note: In function "process_consumed_isinstance":
test_mypy_match.py:13: error: Match[AnyStr] has no attribute "impl_type"
test_mypy_match.py:14: error: Some element of union has no attribute "group"
test_mypy_match.py:16: error: Incompatible return value type (got "Union[Match[Any], str]", expected "str")
mypy 0.4.5, cpython 3.5.2.