I want to define new type which holds list of generic values. For example (simplified as much as possible):
from typing import NamedTuple, TypeVar, List
T = TypeVar('T')
MyType = NamedTuple('MyType', [('values', List[T])])
but this doesn't work and mypy reports following errors:
a.py:4: error: Type variable "a.T" is unbound
a.py:4: note: (Hint: Use "Generic[T]" or "Protocol[T]" base class to bind "T" inside a class)
a.py:4: note: (Hint: Use "T" in function signature to bind "T" inside a function)
Found 1 error in 1 file (checked 1 source file)
Unfortunately, I need python3.4 compatibility (please don't ask why), so I can't use "dataclass" version.
I tried to ignore it by adding #type: ignore to MyType definition, but then mypy wants to add types even in constructions like this:
def do_stuff(x: MyType) -> None:
for v in x.values:
pass
saying: error: Need type annotation for 'v'.
Is there any way to make this work under python3.4 or do I have to keep adding # type: ignore?