pip-deepfreeze 0.5.0

About

pip-deepfreeze aims at doing one thing and doing it well, namely installing and pinning dependencies of Python applications (not libraries) in a virtual environment.

• It is easy to use.

• It is fast.

• It relies on the documented pip command line interface and its ubiquitous requirements file format.

• It assumes your project is configured using a PEP 517 compliant build backend but otherwise makes no assumption on the specific backend used.

• It has first class support for VCS references.

• It is written in Python 3.6+, yet works in any virtual environment that has pip installed, including python 2.

• It is small, simple, with good test coverage and hopefully easy to maintain.

Installation

Using pipx (recommended):

pipx install pip-deepfreeze

Using pip:

pip install --user pip-deepfreeze

Quick start

Make sure your application declares its direct dependencies using setuptools (via the install_requires key in setup.py or setup.cfg), or any other compliant PEP 517 build backend such as flit.

Create and activate a virtual environment using your favorite tool. Run pip list to make sure pip, setuptools and wheel are installed in the virtualenv.

To install your project (in editable mode if supported) in the active virtual environment, go to your project root directory and run:

pip-df sync

If you don’t have one yet, this will generate a file named requirements.txt, containing the exact version of all your application dependencies, as they were installed.

You can then add this requirement.txt to version control, and other people collaborating on the project can install the project and its known good dependencies using pip-df sync (or pip install -r requirements.txt -e . in a fresh virtualenv).

When you add or remove dependencies of your project, run pip-df sync again to update your environment and requirements.txt.

To update one or more dependencies to the latest allowed version, run:

pip-df sync --update DEPENDENCY1 --update DEPENDENCY2 ...

If you need to add some dependencies from VCS references (e.g. when a library with a patch you need is not available as a release on a package index), add the dependency as usual in your project, then add the VCS reference to a file named requirements.txt.in like this:

DEPENDENCYNAME @ git+https://g.c/org/project@branch

Then run pip-df sync. It will update requirements.txt with a VCS reference pinned at the exact commit that was installed (you need pip version 20.1 or greater for this to work). If later you need to update to the HEAD of the same branch, simply use pip-df sync --update DEPENDENCYNAME.

When, later again, your branch is merged upstream and the project has published a release, remove the line from requirements.txt.in and run pip-df sync --update DEPENDENCYNAME to update to the latest released version.

How to

(TODO)

• Initial install (create a venv, and run pip-df sync which will install and generate requirements.txt)

• Add pip options (--find-links, --extra-index-url, etc: in requirements.txt.in)

• Add a dependency that is published in an index or accessible via --find-links (add it in setup.py)

• Install dependencies from direct URLs such as git (add it in setup.py and add the git reference in requirements.txt.in)

• Remove a dependency (remove it from setup.py)

• Update a dependency to the most recent version (pip-df sync --update DEPENDENCY1 --update DEPENDENCY2)

• Update all dependencies to the latest version (pip-df sync --update-all or remove requirements.txt and run pip-df sync)

• Pass options to pip (via requirements.txt.in or via PIP_* environment variables)

• Deploy my project (pip wheel --no-deps requirements.txt -e . --wheel-dir=release, ship the release directory then run pip install --no-index release/*.whl).

CLI reference

Usage: pip-df [OPTIONS] COMMAND [ARGS]...

  A simple pip freeze workflow for Python application developers.

Options:
  -p, --python PYTHON           The python executable to use. Determines the
                                python environment to work on. Defaults to the
                                'python' executable found in PATH.

  -r, --project-root DIRECTORY  The project root directory.  [default: .]
  -v, --verbose
  --install-completion          Install completion for the current shell.
  --show-completion             Show completion for the current shell, to copy
                                it or customize the installation.

  --help                        Show this message and exit.

Commands:
  sync  Install/update the environment to match the project requirements.
  tree  Print the installed dependencies of the project as a tree.

Usage: pip-df sync [OPTIONS]

  Install/update the environment to match the project requirements.

  Install/reinstall the project. Install/update dependencies to the latest
  allowed version according to pinned dependencies in requirements.txt or
  constraints in requirements.txt.in. On demand update of dependencies to to
  the latest version that matches constraints. Optionally uninstall unneeded
  dependencies.

Options:
  -u, --update DEPENDENCY         Make sure DEPENDENCY is upgraded (or
                                  downgraded) to the latest allowed version.
                                  If DEPENDENCY is not part of your
                                  application dependencies anymore, this
                                  option has no effect. This option can be
                                  repeated.

  --update-all                    Upgrade (or downgrade) all dependencies of
                                  your application to the latest allowed
                                  version.

  --editable / --no-editable      Install the project in editable mode.
                                  Defaults to editable if the project supports
                                  it.

  --uninstall-unneeded / --no-uninstall-unneeded
                                  Uninstall distributions that are not
                                  dependencies of the project. If not
                                  specified, ask confirmation.

  --help                          Show this message and exit.

Usage: pip-df tree [OPTIONS]

  Print the installed dependencies of the project as a tree.

Options:
  --help  Show this message and exit.

Other tools

Several other tools exist with a similar or overlapping scope as pip-deepfreeze.

• pip itself. pip-deepfreeze relies extensively on the pip CLI for installation and querying the database of installed distributions. In essence it is a thin wrapper around pip install and pip freeze. Some of the features here may serve as inspiration for future pip evolutions.

• pip-tools. This is the one with the most similar features. Besides the reasons explained in About above I wanted to see if it was possible to do such a thing using the pip CLI only.

• pip-deptree. Works similarly as pip-df tree but needs to be installed in the target virtualenv.

• Poetry

• pipenv

Development

To run tests, use tox. You will get a test coverage report in htmlcov/index.html. An easy way to install tox is pipx install tox.

This project uses pre-commit to enforce linting (among which black for code formating, isort for sorting imports, and mypy for type checking).

To make sure linters run locally on each of your commits, install pre-commit (pipx install pre-commit is recommended), and run pre-commit install in your local clone of the pip-deepfreeze repository.

To release:

• Select the next version number of the form x.y.z.

• towncrier --version x.y.z.

• Inspect and commit the updated HISTORY.rst.

• git tag x.y.z ; git push --tags.

Contributing

We welcome contributions of all kinds.

Please consult the issue tracker to discover the roadmap and known bugs.