pytest-pyodide

library0.59.2pypypi✓ verified 87d ago

A pytest plugin for testing applications that use Pyodide (Python in the browser). Current version 0.59.1, requires Python >=3.11. Active development with frequent releases.

testing

pip install pytest-pyodide

github ↗package ↗changelog ↗

INSTALL

IMPORT

SIG · PYTEST-PYODIDE

pytest-pyodide

testingpythonv0.59.2

Install

7.2s avg

Import

578ms

Disk

212MB

Pass rate

4/ 10

Env Coverage4 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.58.6 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

glibc

py 3.10

✕ build_error

✓ 7.8s

py 3.11

✕ build_error

✓ 7.3s

py 3.12

✕ build_error

✓ 6.8s

py 3.13

✕ build_error

✓ 7s

py 3.9

✕ build_error

212MB installed

● package 212MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

run_in_pyodide

✓ from pytest_pyodide import run_in_pyodide

✗ from pytest_pyodide.decorator import run_in_pyodide

Import path changed; decorator module was flattened.

Minimal test using run_in_pyodide decorator.

import pytest from pytest_pyodide import run_in_pyodide @run_in_pyodide(packages=['numpy']) def test_numpy_in_browser(selenium): import numpy as np assert np.array([1,2,3]).sum() == 6

Debug

Known issues

breakingClassic web worker support dropped in 0.59.0. Tests must target modern browsers (Chrome/Firefox) via Selenium or Playwright.

fix

Use selenium fixture or switch to Playwright driver.

affects: >=0.59.0

deprecatedThe 'selenium' fixture is deprecated in favor of browser-agnostic fixtures. Use 'webdriver' or 'playwright_browser' instead.

fix

Replace 'selenium' with 'webdriver' or configure Playwright.

affects: >=0.58.0

gotchaPackages must be listed explicitly in @run_in_pyodide or added via conftest.py's pyodide_packages hook. Standard library modules like json, math are always available.

fix

Add required packages in the decorator: @run_in_pyodide(packages=['numpy', 'pandas'])

affects: all

gotchaTests run in a separate browser process; global state is not shared between tests. Each test receives a fresh Pyodide environment.

fix

Use fixtures to set up shared state explicitly.

affects: all

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'pytest_pyodide'

pytest-pyodide not installed or installed in wrong environment.

fix

Ensure you are in the correct Python environment and run: pip install pytest-pyodide

Fixture 'selenium' not found

Selenium driver is not installed or the fixture has been renamed.

fix

Install selenium (pip install selenium) or use the Playwright driver: pip install playwright && playwright install

ValueError: Package 'pandas' is not loaded. Did you include it in the decorator?

Third-party packages must be explicitly listed in the run_in_pyodide decorator's packages argument.

fix

Change decorator to @run_in_pyodide(packages=['pandas'])

Upgrade

Version history

0.59.2latest on PyPI · released Apr 27, 2026

Audit

Dependencies

pytestrequiredRequired test framework

pyodide-pyrequiredPyodide runtime

playwrightoptionalBrowser automation for testing

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/pyodide/pytest-pyodide ↗

packagehttps://pypi.org/project/pytest-pyodide/ ↗

changeloghttps://github.com/pyodide/pytest-pyodide/blob/main/CHANGELOG.md ↗