(🎁) Error when `__get__` returns incompatible type
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feature
topic-descriptors
topic-runtime-semantics
- Dominant language
- Python
- Stars
- 20.6k
- Forks
- 3.3k
- PR merge metrics
- PR metrics pending
Description
class A: ...
class B(A):
def __get__(self, i, o) -> int:
return 1
class Something:
a: A = B()
reveal_type(Something.a) # Revealed type is "A"
actual value at runtime is int
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Use the shown get descriptor example as the entry point and trace how mypy infers the type of Something.a. Add a regression test for the incompatible return type; done means the inferred type reflects the runtime int rather than reporting only A.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- tooling
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100