While the first complaint is just a reflect of the lack of good tutorials on mypy, the second one is very valid: I too wish for automatic type detection for obvious cases.
What's more, while I found mypy useful myself in several instances, it's still cumbersome to use:
- you must know to use the magic command line arguments to avoid mypy complaining about other libs and imports all the time
- you need to use List[], Dict[], Set[], Iteratble[], Tuple[], etc. instead of list[], dict[], set[], iter[], tuple[], etc., which means an import in almost every file and a very unnatural workflow.
- you need to use Union and instead of |. This is ridiculous. I have to do:
from typing import Union, List
def mask(...) -> List[Union[bool, int]]
Instead of:
def mask(...) -> list[bool|int]
And Guido explicitly rejected the proposal for those on github despite the fact most imports are due to those.
Now, mypy has improved a lot. It's way faster, shows many more things that before, way less false positive, and has support for duck typing and dunder methods (named "protocol").
But it's sad to thing TypeScript is actually easier to use. Having a JS tech easier to use than a Python tech is a good sign we can improve things.