mypy Skipping analyzing / Library stubs not installed (tested)

mypy has three import errors: Skipping analyzing "x": module is installed, but missing library stubs or py.typed marker (no types available: ignore that module), Library stubs not installed for "x" (run pip install types-x), and Cannot find implementation or library stub (mypy cannot see the package at all).

1. The three import errors side by side

Output (mypy 2.4.0, Python 3.13.5; celery installed, tabulate and notinstalled not installed):

$ cat b1.py
import celery
import tabulate
import notinstalled
$ mypy b1.py
b1.py:1: error: Skipping analyzing "celery": module is installed, but missing library stubs or py.typed marker  [import-untyped]
b1.py:1: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
b1.py:2: error: Library stubs not installed for "tabulate"  [import-untyped]
b1.py:2: note: Hint: "python3 -m pip install types-tabulate"
b1.py:2: note: (or run "mypy --install-types" to install all missing stub packages)
b1.py:3: error: Cannot find implementation or library stub for module named "notinstalled"  [import-not-found]
Found 3 errors in 1 file (checked 1 source file)

$ mypy --ignore-missing-imports b1.py
Success: no issues found in 1 source file

$ cat mypy.ini
[mypy]

[mypy-celery.*]
ignore_missing_imports = True
$ mypy b1.py
b1.py:2: error: Library stubs not installed for "tabulate"  [import-untyped]
b1.py:3: error: Cannot find implementation or library stub for module named "notinstalled"  [import-not-found]
Found 2 errors in 1 file (checked 1 source file)

2. What each one means

• Skipping analyzing "celery": module is installed, but missing library stubs or py.typed marker: the package is there but ships no type information and typeshed has no stub package for it. Ignore it per module (the [mypy-celery.*] section, which also covered the top-level celery import here) or look for a third-party stub package.
• Library stubs not installed for "tabulate": typeshed has a stub package for it. Install it as the hint says: pip install types-tabulate, or mypy --install-types. This appeared even though tabulate itself was not installed in this environment.
• Cannot find implementation or library stub for module named "notinstalled" (code import-not-found): mypy cannot find the module at all. Usually mypy runs in a different environment than your packages (run python -m mypy from the project's venv), or the path needs MYPYPATH.

3. Ignoring

--ignore-missing-imports silenced all three at once, including the real import-not-found one, so prefer the per-module config section shown above, which left the other two errors visible.

Written with AI assistance. Measured on 2026-10-23 with mypy 2.4.0 and Python 3.13.5 on Linux. Commands ran verbatim and the output was pasted unedited. PlainTables is our extension; mypy is free.