self.x: str = 1000. Why is this not an error?

[kurtgn]

The question is basically in the header.

Why is this an error:

count: str = 1000  # expression has type "int", variable has type "str"

and this is not:

class Counter:
    def __init__(self):
        self.count: str = 1000
c = Counter()

I have the latest mypy as of today:

mypy 0.740 
├── mypy-extensions 0.4.3 
├── typed-ast 1.4.0
└── typing-extensions 3.7.4.1

[emmatyping]

Hi, it looks like __init__ is not annotated, thus mypy will skip it by default. I recommend that you check out the docs to learn more.

[JelleZijlstra]

I feel like it'd be reasonable to change the behavior though. The intent behind mypy's behavior of not type checking unannotated methods is to enable gradual typing: users can gradually add more typing to their codebase, without worrying about type errors in functions that don't have annotations yet. But clearly if the user put a variable annotation in the function, they did intend to apply typing to the function and would expect mypy to typecheck it.

[emmatyping]

But clearly if the user put a variable annotation in the function, they did intend to apply typing to the function and would expect mypy to typecheck it.

Yeah, I think this is a reasonable idea.

[ilevkivskyi]

Yeah, I think this is a reasonable idea.

This is then essentially a duplicate of #3948