piptools

piptools is a set of command-line utilities for Python packaging. It helps manage project dependencies by generating and synchronizing requirements files. The core idea is to separate development dependencies from production dependencies, making it easier to manage different environments.

The main commands are pipcompile and pipsync. pipcompile takes a source file, typically named requirements.in, which lists direct dependencies. It then resolves all transitive dependencies and outputs a complete, pinned requirements.txt file. This file contains exact versions for all packages, ensuring reproducible builds. pipcompile can also handle different environments, such as testing or development, by using separate input files.

pipsync is used to install the dependencies specified in a generated requirements.txt file. It ensures that the installed packages in a virtual environment exactly match the versions listed in the file. This synchronization step is crucial for maintaining consistency across different machines and for deployment.

By using piptools, developers can avoid common issues related to dependency management, such as conflicting package versions or the "it works on my machine" problem. It promotes a more robust and predictable development workflow. The tool is designed to be integrated into CI/CD pipelines to automate dependency updates and installations.