"Incompatible types in assignment" when using _ as throwaway variable

[vors]

Should _ get a special treatment?

Repro

import os

for _ in range(3): # throw-away _
    root, _ = os.path.split("C:\\123") # throw-away _

Expected

No errors

Actual

foo.py:4: error: Incompatible types in assignment (expression has type "str", variable has type "int")

[gvanrossum]

It's been proposed before, there may even be an open issue for it already, but GitHub can't seem to search for "_". If someone submits a PR I'm happy to review it.

[vors]

Oh, sorry I didn't search extensively before filling.

I aslo tried to work-around it with

import os
from typing import Any

for _ in range(3):  # type: Any
    root, _ = os.path.split("C:\\123")

And that produces foo.py:4: error: Parse error before "Any" which seems like a separate issue.

[gvanrossum]

That parse error should be gone if you use the fast parser (which is default in master and will soon be the only one).

[ilevkivskyi]

Here is the issue that Guido mentioned #465.