This blog post is a comprehensive guide for implementing a secure CI/CD pipeline specifically for Python packages using GitLab CI. It details how to sign and attest packages, ensuring integrity and authenticity throughout the software supply chain. The guide includes insights into pipeline stages such as building, signing, verifying, and publishing packages with an emphasis on using Sigstore's Cosign for cryptographic verification. It serves as an essential resource for developers looking to enhance the security of their package distribution processes.