Last modified: Jun 01, 2025 By Alexander Williams
Install Pytest-cov for Coverage Reports
Testing is crucial in Python development. Coverage reports help track tested code. Pytest-cov integrates with pytest to generate these reports.
Table Of Contents
What is Pytest-cov?
Pytest-cov is a plugin for pytest. It measures code coverage during tests. This helps identify untested parts of your codebase.
Prerequisites
Before installing pytest-cov, ensure you have:
- Python 3.6+ installed
- Basic knowledge of pytest
- A project with tests
If you need pytest basics, check our guide on Install Bottle Web Framework for Python.
Install Pytest-cov
Install pytest-cov using pip:
pip install pytest-cov
This installs pytest-cov and its dependencies. Verify installation:
pytest --version
Basic Usage
Run tests with coverage using:
pytest --cov=your_package tests/
Replace your_package
with your module name. This generates a coverage report.
Understanding the Output
A sample output looks like:
----------- coverage: platform linux, python 3.8.5 -----------
Name Stmts Miss Cover
-------------------------------------
your_module.py 15 2 87%
The report shows statements, missed lines, and coverage percentage.
Generating HTML Reports
For detailed reports, generate HTML:
pytest --cov=your_package --cov-report=html tests/
This creates an htmlcov
directory. Open index.html
in a browser.
Configuration
Add a .coveragerc
file to customize coverage:
[run]
source = your_package
omit = */tests/*
This configures coverage source and omitted files.
Advanced Features
Pytest-cov offers advanced features:
- Branch coverage
- Coverage thresholds
- Multiple report formats
For similar tools, see our guide on Install Pexpect in Python for Automation.
Common Issues
Some common problems include:
- Missing source files
- Incorrect paths
- Version conflicts
Ensure paths are correct and versions compatible.
Conclusion
Pytest-cov is essential for Python testing. It provides valuable coverage insights. Install it today to improve your testing workflow.
For more Python tools, check our guide on Install PsySH for Python IPython Shell.