Python requirements.txt Generator

What Is requirements.txt

requirements.txt is the standard dependency specification file for Python projects. It lists the Python packages required to run the project, optionally with version constraints, enabling anyone to recreate the exact environment using pip install -r requirements.txt. This file is the Python ecosystem's equivalent of package.json (Node.js) or Gemfile (Ruby).

This tool generates properly formatted requirements.txt files with common packages for various Python project types, including version pinning best practices and dependency grouping.

Dependency Specification Syntax

Common Use Cases

• New project setup: Generate a requirements.txt with common packages for your project type (web API, data science, machine learning, CLI tool, scraping)
• Environment reproducibility: Pin exact versions to ensure all team members and CI/CD pipelines use identical package versions
• Docker image building: Include requirements.txt in Docker builds for consistent, reproducible container images
• Virtual environment documentation: Document which packages a virtual environment contains for onboarding new developers
• Dependency auditing: Review installed packages for known vulnerabilities using tools like pip-audit or safety

Best Practices

1. Pin exact versions in production — Use == for production requirements to ensure reproducible deployments. Generated with: pip freeze > requirements.txt
2. Use separate requirements files — Maintain requirements.txt (production), requirements-dev.txt (development tools), and requirements-test.txt (testing dependencies).
3. Audit dependencies regularly — Run pip-audit or safety check to scan for packages with known CVEs. Set up automated scanning in CI/CD.
4. Use virtual environments always — Never install project dependencies globally. Use venv, virtualenv, or conda to isolate project dependencies.
5. Consider modern alternatives — For new projects, evaluate pyproject.toml (PEP 621) with pip, Poetry, or PDM as more modern dependency management approaches that offer lock files and dependency resolution.
6. Hash-check for security — Use --require-hashes with pip to verify package integrity: pip install --require-hashes -r requirements.txt. This prevents supply chain attacks through tampered packages.