Coverage.py

Installation and Setup

Install it from PyPI:

• Windows
• Linux + macOS

PS> py -m pip install --user coverage
PS> coverage --version

$ python -m pip install coverage

Optional configuration with a .coveragerc or pyproject.toml file:

[run]
branch = True
source = src

[report]
show_missing = True
omit =
    tests/*

Key Features

• Supports line and branch coverage measurement with optional exclusion rules and pragmas.
• Offers selectable measurement cores through the [run] core setting, including the sysmon core built on sys.monitoring, which is the default on Python 3.14 and later.
• Supports multiple report formats including terminal, HTML, XML, JSON, and LCOV.
• Provides concurrency support for multiprocessing, gevent, greenlet, and eventlet through the [run] concurrency setting, and can measure Python subprocesses with [run] patch = subprocess, combining the collected data afterward.
• Offers configurable measurement through .coveragerc or pyproject.toml.
• Supports data management commands to combine, erase, and annotate results for CI or local workflows.

Usage

Measure coverage while running your test suite:

$ coverage run -m pytest -q

Show a summary in the terminal with missing lines:

$ coverage report -m

Generate an HTML report:

$ coverage html

Export machine-readable outputs:

$ coverage xml
$ coverage json

Reset collected data and start fresh:

$ coverage erase

Related Resources

Tutorial

pytest Tutorial: Effective Python Testing

Master pytest with this hands-on tutorial. Learn fixtures, parametrize, marks, and plugins to write fast, effective Python test suites.

intermediate testing

For additional information on related topics, take a look at the following resources:

• Testing Your Code With pytest (Course)
• Test-Driven Development With pytest (Course)
• Testing Your Code With Python's unittest (Course)
• Effective Testing with Pytest (Quiz)