ModuleNotFoundError: No module named 'pytest_xdist'

TL;DR

Import xdist, not pytest_xdist. The package is called pytest-xdist on PyPI but the importable module is just xdist. If you actually need the plugin, pip install pytest-xdist is the fix.

ModuleNotFoundError: No module named 'pytest_xdist'

Fix it

1. Fix the import. Change import pytest_xdist to import xdist.

   • Expected: the import succeeds (if pytest-xdist is installed).

2. If it still fails, install the package: python -m pip install pytest-xdist.

   • Expected: Successfully installed pytest-xdist-....

When this applies

• You guessed the module name from the PyPI package name.
• Code or docs you copied use the wrong import.

When it does not apply

• If import xdist also fails, the package is genuinely not installed.

Tool compatibility

pytest-xdist 2.x/3.x. The module has always been xdist.

Why it happens

PyPI package names and import names often differ. The pytest- prefix is a naming convention for plugins; the module drops it.

Edge cases

• Same trap as pytest-cov (module pytest_cov, which keeps the prefix) versus pytest-xdist (module xdist, which drops it). Check each plugin's docs.

The pytest-xdist documentation and PyPI page (https://pypi.org/project/pytest-xdist/) show the package name pytest-xdist while the plugin registers under the xdist entry point and module. Guessing import pytest_xdist from the package name is the standard mistake; the correct module is xdist.