Mypy exclude doesn't work as expected

[artsiomkaltovich]

Bug Report

I want to exclude a folder from mypy checks, but it still inspect it.

mypy -v output:

LOG:  Mypy Version:           1.13.0
LOG:  Config File:            /Users/a_kaltovich/projects/mypy_doesnot_work/pyproject.toml
LOG:  Configured Executable:  /Users/a_kaltovich/projects/mypy_doesnot_work/.venv/bin/python
LOG:  Current Executable:     /Users/a_kaltovich/projects/mypy_doesnot_work/.venv/bin/python
LOG:  Cache Dir:              .mypy_cache
LOG:  Compiled:               True
LOG:  Exclude:                ['libs']

To Reproduce

• please refer to this project https://github.com/artsiomkaltovich/mypy_exclude
• git clone [email protected]:artsiomkaltovich/mypy_exclude.git
• execute mypy .

Expected Behavior

libs folder is excluded

Actual Behavior

libs/lib1/lib1.py:2: error: Incompatible return value type (got "int", expected "str") [return-value]

Your Environment

Refer to pyproject.toml file.

[brianschubert]

Hi! This is expected behavior. The exclude option controls how mypy discovers files to type check (you can think of it as refining the "entry points" for type checking). However it doesn't affect the way that the discovered files are type checked. In particular, it doesn't affect the way mypy follow imports. If any of the files being analyzed import a module from libs, then by default that module will be analyzed as well (along with any modules that it imports). You can refer to Following Imports from the mypy docs for more details on how this works and what configuration options are available.

If you want to suppress errors for modules from libs, you can try setting follow_imports to silent for those modules:

[[tool.mypy.overrides]]
module = "libs.*"
follow_imports = "silent"