8000 Enum final checking false positive in complex case · Issue #11702 · python/mypy · GitHub
[go: up one dir, main page]
Skip to content
8000

Enum final checking false positive in complex case #11702

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom
Closed
JukkaL opened this issue Dec 10, 2021 · 3 comments
Closed

Enum final checking false positive in complex case #11702

JukkaL opened this issue Dec 10, 2021 · 3 comments
Labels
bug mypy got something wrong false-positive mypy gave an error on correct code priority-0-high

Comments

@JukkaL
Copy link
Collaborator
JukkaL commented Dec 10, 2021

This code generates a false positive, but weirdly I can only reproduce it if the base class is defined in a different module:

from mod import E

class EE(E):  # Cannot inherit from final class "E"
    X = (0, "")
# mod.py
from enum import Enum
from typing import Optional, Type

class E(int, Enum):
    def __init__(self, _: int, x: Optional[str] = None) -> None:
        self.x = x

    def __new__(cls: Type['E'], value: int, x: Optional[str] = None) -> 'E':
        enum = int.__new__(cls, value)
        enum._value_ = value
        enum.x = x
        return enum

The code works at runtime.

This started happening as a side effect of #11247.

Marking as high priority, since this is a regression. If it seems clear that this may only happen in pretty specialized circumstances, we can perhaps lower the priority.

cc @sobolevn
@JukkaL JukkaL added bug mypy got something wrong priority-0-high false-positive mypy gave an error on correct code labels Dec 10, 2021
@JukkaL JukkaL mentioned this issue Dec 10, 2021
Closed
@sobolevn
Copy link
Member

See https://github.com/python/mypy/pull/11579/files
Will it fix this case?

@sobolevn
Copy link
Member

Looks like it fixes this issue indeed!
Снимок экрана 2021-12-10 в 20 35 04
Снимок экрана 2021-12-10 в 20 35 20

@JukkaL
Copy link
Collaborator Author
JukkaL commented Dec 10, 2021

Excellent! I can review the PR early next week.

@JukkaL JukkaL closed this as completed in 6de254e Dec 21, 2021
JukkaL pushed a commit that referenced this issue Dec 21, 2021
@sobolevn @JukkaL
Enums with annotations and no values are fine to be subclassed (#11579)
b31b06b 
Closes #11578. Closes #11702.
tushar-deepsource pushed a commit to DeepSourceCorp/mypy that referenced this issue Jan 20, 2022
@sobolevn @tushar-deepsource
Enums with annotations and no values are fine to be subclassed (pytho…
7f28792 
…n#11579)

Closes python#11578. Closes python#11702.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
bug mypy got something wrong false-positive mypy gave an error on correct code priority-0-high
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
2 participants
@JukkaL @sobolevn
0