Give a warning if a local variable is assigned to but never read

Open
#76 8 comments 1 reaction 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
25/100
Issue type
Feature
Clarity
Needs clarification
Activity status
Stale
Tech stack
python
Domain
devtools

Research direction

No file, test, or entry point is named. Start by locating the type checker's handling of local-variable assignments and the existing warning configuration; done means an explicitly enabled warning is emitted for assigned-but-never-read locals without warning by default.

Written by the indexing model from the issue text.

Description

feature priority-1-normal topic-variable-scope

The type checker should give a warning if a local variable is only assigned to but never read.
This is usually a result of a misspelled variable name.

Perhaps only do this if warnings have been explicitly enabled using a command line option or via some other mechanism.

Dominant language
Python
Stars
20.6k
Forks
3.3k
Avg merge
1d 18h
Merged PRs (30d)
54

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.

More from python/mypy

All issues in python/mypy

Similar issues

More Python issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.