NameError: name 'List' is not defined

Question

I'm really unsure why this isn't working. Here is the important part of the code (it's from a leetcode challenge). The first line throws the NameError.

def totalFruit(self, tree: List[int]) -> int:
    pass

If I try importing List first I get an error No module named 'List'. I'm using Python 3.7.3 from Anaconda.

Answer 1

To be able to annotate what types your list should accept, you need to use typing.List

from typing import List

So did you import List?

Update

If you're using Python > 3.9, see @Adam.Er8's answer