Confusing error message when setting item in a heterogeneous dict

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#2,900 10 comments 3 reactions 0 assignees View on GitHub

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
38/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
python
Domain
devtools

Research direction

Start by running the provided heterogeneous-dict example with mypy and capture the complete diagnostic; the issue does not name a source file or test. Trace the type-checking path that reports the error and add or update a regression test for this snippet, with completion defined by a clear, appropriate diagnostic.

Written by the indexing model from the issue text.

Description

feature priority-1-normal topic-inference topic-typed-dict topic-usability

This simple piece of code throws a mypy error:

foo = dict(junk=1, bar=dict(yo=3))
foo['bar']['yo'] = 5

I've only tested on the last release (0.471)

Dominant language
Python
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Avg merge
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Merged PRs (30d)
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