python / python/mypy

mypy --strict doesn't handle wildcard imports of modules that do 'import foo as bar'

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bug
Dominant language
Python
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Description

To Reproduce

a.py:

import logging as log

b.py

from a import *
log.info("Hello")

Expected Behavior

b.py should typecheck without any issue. At runtime it works fine and there are no runtime type errors, only mypy complains.

Actual Behavior

$ python3 -m mypy --strict /tmp/b.py
b.py:2: error: Name "log" is not defined  [name-defined]
Found 1 error in 1 file (checked 1 source file)

Your Environment

  • Mypy version used: 1.10.0
  • Mypy command-line flags: --strict
  • Mypy configuration options from mypy.ini (and other config files): None
  • Python version used: 3.12.3

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 by running the a.py and b.py reproducer with python3 -m mypy --strict /tmp/b.py, then trace how wildcard imports handle the aliased import. Done means the example typechecks without the [name-defined] error and a regression test covers this behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
devtools, tooling
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Clearly specified
Newbie friendliness
48/100

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