__path__ is inferred an Iterable[str] rather than list

[aDotInTheVoid]

Note: This is a regression of #1032. I've confirmed it appears in the latest released version.

Describe the bug

With the following code:

./mcve
└── __init__.py

mcve/__init__.py:

print(__path__[0])

(Code sample in pyright playground)

Pyright give errors:

% pyright ./mcve 
/Users/aloenr01/tmp/mcve/__init__.py
  /Users/aloenr01/tmp/mcve/__init__.py:1:7 - error: "__getitem__" method not defined on type "Iterable[str]" (reportIndexIssue)
1 error, 0 warnings, 0 informations 

But the code works fine:

% python3
Python 3.12.9 (main, Feb  4 2025, 14:38:38) [Clang 16.0.0 (clang-1600.0.26.6)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import mcve
/Users/aloenr01/tmp/mcve

VS Code extension or command-line

Command line: pyright 1.1.396

[erictraut]

In response to bug #1032, I changed this from Iterable[str] to list[str] back in 2020. In early 2021, I reverted this change for reasons I don't recall. Unfortunately, I can't find the bug report or question that prompted the revert.

The type list[str] is narrower than what is required by the runtime, so changing the type of __path__ to list[str] would be incorrect. The type Iterable[str] is correct but probably wider than necessary. Based on the typeshed stubs, it appears that the correct type for this symbol is MutableSequence[str]. I'll change it to that.