python / python/mypy

"Trying to read deleted variable" false negative when importing deleted variable

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bug
Dominant language
Python
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Description

# asdf.py
a = 1
del a

print(a) # error: Trying to read deleted variable
# main.py
from asdf import a # no error. runtime ImportError: cannot import name 'a' from 'asdf'

print(a) # no error

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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 two-file reproduction in asdf.py and main.py, then run mypy on the example to confirm the missing diagnostics. Trace how the deleted name is handled across the import and later access; done means mypy reports the invalid import and subsequent use consistently with the direct access in asdf.py.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
devtools
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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