["python","python-typing","nameerror"]
NameError: name 'List' is not defined

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.
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? If you're using Python >= 3.9, see @Adam.Er8's answer for the new syntax.