[roywiggins]

I always just used pip-tools. Your requirements.in is the file that is human-readable and -writable, and sets your top-level deps and the version ranges you want. requirements.txt is your lockfile that you generate from .in with pip-compile. pip-compile writes out comments specifying from where each package in requirements.txt is being required.

uv does it a lot faster and generates requirements.txts that are cross-platform, which is a nice improvement.