Cosmic Ray: mutation testing for Python
“Four human beings – changed by space-born cosmic rays into something more than merely human.”
—The Fantastic Four
Cosmic Ray is a mutation testing tool for Python 3.
It makes small changes to your source code, running your test suite for each one. Here’s how the mutations look:
Read the full documentation at readthedocs.
Contributing
The easiest way to contribute is to use Cosmic Ray and submit reports for defects or any other issues you come across. Please see CONTRIBUTING.rst for more details.
2 maintainers
Metadata
2 maintainers
Release files for cosmic-ray 8.8.0
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | Provenance | Actions |
|---|---|---|---|---|
| cosmic_ray-8.8.0.tar.gz | 1.7 MB | With provenance | Details for cosmic_ray-8.8.0.tar.gz |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Actions Reset |
|---|---|---|---|---|
| cosmic_ray-8.8.0-py3-none-any.whl | Python 3 | none | any | Details for cosmic_ray-8.8.0-py3-none-any.whl |
Total release size: 1.7 MB
Release files / cosmic_ray-8.8.0.tar.gz
| Download URL | cosmic_ray-8.8.0.tar.gz |
|---|---|
| Size | 1.7 MB |
| Tags | Source |
|
SHA-256 checksum How to use checksums |
ca5a89ef425311fc3e1e9ace16136bc3e3da15396144dd1d87f4dfbeb3285ace
|
|
BLAKE2b-256 checksum How to use checksums |
a43b759c0280100279c4a01d22ea65f1d25c056119ab6941102023d33cb7c487
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.16
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Nov 8, 2026.
Transparency logRelease files / cosmic_ray-8.8.0-py3-none-any.whl
| Download URL | cosmic_ray-8.8.0-py3-none-any.whl |
|---|---|
| Size | 62.5 kB |
| Tags | Python 3 |
|
SHA-256 checksum How to use checksums |
d8fcec8ec9b3954a47b6232d5b629e5b9875862c87fdd936fecf90c79b69468b
|
|
BLAKE2b-256 checksum How to use checksums |
0264df1221c18d313d1fe7414712a380e7844f6bdca39b4166dc0c31e77f97d4
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.16
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Nov 8, 2026.
Transparency logSecurity for cosmic-ray 8.8.0
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
Full provenance
Both files in this release have been uploaded with provenance metadata.
Attestation for cosmic_ray-8.8.0.tar.gz
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Nov 8, 2026.
Transparency logA note on package security
PyPI is a repository for distributing packages, not a service for auditing them. While third-party security researchers and our staff do their best to detect and remove malicious packages, PyPI cannot guarantee the quality, security or suitability of any given package.
To learn more about protecting yourself from malicious actors, visit our package security documentation.
