python / python/mypy

Function signature matching fails at import

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#18,060 4 comments 0 reactions 0 assignees View on GitHub

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bug topic-error-reporting
Dominant language
Python
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Description

Bug Report

The provided test defines a function with the same type signature in two ways, directly and through import.

mypy objects that functions are incompatible.

To Reproduce

https://gist.github.com/mypy-play/a5f51cd9246e6478516af53493402890

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the linked mypy-play reproduction and confirm the differing results between the direct and imported function definitions. Trace the import-related signature comparison, then add a regression test covering the reproduction and verify that mypy accepts the equivalent signatures.

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
35/100

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