Switching Pip to Uv in a Dockerized Flask / Django App

It's worth noting that uv also supports a workflow that directly replaces pyenv, virtualenv and pip without mandating a change to a lockfile/pyproject.toml approach.

uv python pin <version> will create a .python-version file in the current directory.

uv virtualenv will download the version of Python specified in your .python-version file (like pyenv install) and create a virtualenv in the current directory called .venv using that version of Python (like pyenv exec python -m venv .venv)

uv pip install -r requirements.txt will behave the same as .venv/bin/pip install -r requirements.txt.

uv run <command> will run the command in the virtualenv and will also expose any env vars specified in a .env file (although be careful of precedence issues: https://github.com/astral-sh/uv/issues/9465)

Doesn't it store the python version in the pyproject.toml though, is the python version file needed?

It’s not:

> uv will respect Python requirements defined in requires-python in the pyproject.toml file during project command invocations. The first Python version that is compatible with the requirement will be used, unless a version is otherwise requested, e.g., via a .python-version file or the --python flag.

— https://docs.astral.sh/uv/concepts/python-versions/#project-...