python / python/mypy

(🐞) false positive expression contains `Any`, type parameters assumed to be `Any` when assigning to a variable of type `Any`

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bug
Dominant language
Python
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Description

from typing import Any

a: Any

a = {1: 2}  # error: Expression type contains "Any" (has type "Dict[Any, Any]")

Doesn't look to me like the expression contains Any.

playground

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First steps

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Research direction

Start with the linked mypy playground reproducer using strict and disallow-any-expr, then trace how the dictionary expression is inferred when assigned to a variable annotated Any. Done means this case no longer reports that the expression contains Any, with coverage added for the regression.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
compilers
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Clearly specified
Newbie friendliness
45/100

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