gecko-dev/third_party/python/pip-tools/README.rst

|jazzband| |pypi| |pyversions| |buildstatus-travis| |buildstatus-appveyor| |codecov|

==================================
pip-tools = pip-compile + pip-sync
==================================

A set of command line tools to help you keep your ``pip``-based packages fresh,
even when you've pinned them.  `You do pin them, right?`_

.. image:: https://github.com/jazzband/pip-tools/raw/master/img/pip-tools-overview.png
   :alt: pip-tools overview for phase II

.. |buildstatus-travis| image:: https://img.shields.io/travis/jazzband/pip-tools/master.svg?logo=travis
   :alt: Travis CI build status
   :target: https://travis-ci.org/jazzband/pip-tools
.. |buildstatus-appveyor| image:: https://img.shields.io/appveyor/ci/jazzband/pip-tools/master.svg?logo=appveyor
   :alt: AppVeyor build status
   :target: https://ci.appveyor.com/project/jazzband/pip-tools
.. |codecov| image:: https://codecov.io/gh/jazzband/pip-tools/branch/master/graph/badge.svg
   :alt: Coverage
   :target: https://codecov.io/gh/jazzband/pip-tools
.. |jazzband| image:: https://jazzband.co/static/img/badge.svg
   :alt: Jazzband
   :target: https://jazzband.co/
.. |pypi| image:: https://img.shields.io/pypi/v/pip-tools.svg
   :alt: PyPI version
   :target: https://pypi.org/project/pip-tools/
.. |pyversions| image:: https://img.shields.io/pypi/pyversions/pip-tools.svg
   :alt: Supported Python versions
   :target: https://pypi.org/project/pip-tools/
.. _You do pin them, right?: http://nvie.com/posts/pin-your-packages/


Installation
============

As part of a Python project's environment tooling (similar to ``pip``), it's
recommended to install ``pip-tools`` in each project's `virtual environment`_:

.. code-block:: bash

    $ source /path/to/venv/bin/activate
    (venv)$ pip install pip-tools

**Note**: all of the remaining example commands assume you've activated your
project's virtual environment.

.. _virtual environment: https://packaging.python.org/tutorials/installing-packages/#creating-virtual-environments

Example usage for ``pip-compile``
=================================

The ``pip-compile`` command lets you compile a ``requirements.txt`` file from
your dependencies, specified in either ``setup.py`` or ``requirements.in``.

Run it with ``pip-compile`` or  ``python -m piptools compile``. If you use
multiple Python versions, you can run ``pip-compile`` as ``py -X.Y -m piptools
compile`` on Windows and ``pythonX.Y -m piptools compile`` on other systems.

Requirements from ``setup.py``
------------------------------

Suppose you have a Flask project, and want to pin it for production.
If you have a ``setup.py`` with ``install_requires=['Flask']``, then run
``pip-compile`` without any arguments:

.. code-block:: bash

    $ pip-compile
    #
    # This file is autogenerated by pip-compile
    # To update, run:
    #
    #    pip-compile --output-file requirements.txt setup.py
    #
    click==6.7                # via flask
    flask==0.12.2
    itsdangerous==0.24        # via flask
    jinja2==2.9.6             # via flask
    markupsafe==1.0           # via jinja2
    werkzeug==0.12.2          # via flask

``pip-compile`` will produce your ``requirements.txt``, with all the Flask
dependencies (and all underlying dependencies) pinned.  You should put
``requirements.txt`` under version control.

Without ``setup.py``
--------------------

If you don't use ``setup.py`` (`it's easy to write one`_), you can create a
``requirements.in`` file to declare the Flask dependency:

.. code-block:: ini

    # requirements.in
    Flask

Now, run ``pip-compile requirements.in``:

.. code-block:: bash

    $ pip-compile requirements.in
    #
    # This file is autogenerated by pip-compile
    # To update, run:
    #
    #    pip-compile --output-file requirements.txt requirements.in
    #
    click==6.7                # via flask
    flask==0.12.2
    itsdangerous==0.24        # via flask
    jinja2==2.9.6             # via flask
    markupsafe==1.0           # via jinja2
    werkzeug==0.12.2          # via flask

And it will produce your ``requirements.txt``, with all the Flask dependencies
(and all underlying dependencies) pinned.  You should put both
``requirements.in`` and ``requirements.txt`` under version control.

.. _it's easy to write one: https://packaging.python.org/guides/distributing-packages-using-setuptools/#configuring-your-project

Using hashes
------------

If you would like to use *Hash-Checking Mode* available in ``pip`` since
version 8.0, ``pip-compile`` offers ``--generate-hashes`` flag:

.. code-block:: bash

    $ pip-compile --generate-hashes requirements.in
    #
    # This file is autogenerated by pip-compile
    # To update, run:
    #
    #    pip-compile --generate-hashes --output-file requirements.txt requirements.in
    #
    click==6.7 \
        --hash=sha256:29f99fc6125fbc931b758dc053b3114e55c77a6e4c6c3a2674a2dc986016381d \
        --hash=sha256:f15516df478d5a56180fbf80e68f206010e6d160fc39fa508b65e035fd75130b \
        # via flask
    flask==0.12.2 \
        --hash=sha256:0749df235e3ff61ac108f69ac178c9770caeaccad2509cb762ce1f65570a8856 \
        --hash=sha256:49f44461237b69ecd901cc7ce66feea0319b9158743dd27a2899962ab214dac1
    itsdangerous==0.24 \
        --hash=sha256:cbb3fcf8d3e33df861709ecaf89d9e6629cff0a217bc2848f1b41cd30d360519 \
        # via flask
    jinja2==2.9.6 \
        --hash=sha256:2231bace0dfd8d2bf1e5d7e41239c06c9e0ded46e70cc1094a0aa64b0afeb054 \
        --hash=sha256:ddaa01a212cd6d641401cb01b605f4a4d9f37bfc93043d7f760ec70fb99ff9ff \
        # via flask
    markupsafe==1.0 \
        --hash=sha256:a6be69091dac236ea9c6bc7d012beab42010fa914c459791d627dad4910eb665 \
        # via jinja2
    werkzeug==0.12.2 \
        --hash=sha256:903a7b87b74635244548b30d30db4c8947fe64c5198f58899ddcd3a13c23bb26 \
        --hash=sha256:e8549c143af3ce6559699a01e26fa4174f4c591dbee0a499f3cd4c3781cdec3d \
        # via flask

Updating requirements
---------------------

To update all packages, periodically re-run ``pip-compile --upgrade``.

To update a specific package to the latest or a specific version use the
``--upgrade-package`` or ``-P`` flag:

.. code-block:: bash

    $ pip-compile --upgrade-package flask  # only update the flask package
    $ pip-compile --upgrade-package flask --upgrade-package requests  # update both the flask and requests packages
    $ pip-compile -P flask -P requests==2.0.0  # update the flask package to the latest, and requests to v2.0.0

You can combine ``--upgrade`` and ``--upgrade-package`` in one command, to
provide constraints on the allowed upgrades. For example to upgrade all
packages whilst constraining requests to the latest version less than 3.0:

.. code-block:: bash

    $ pip-compile --upgrade --upgrade-package 'requests<3.0'

Output File
-----------

To output the pinned requirements in a filename other than
``requirements.txt``, use ``--output-file``. This might be useful for compiling
multiple files, for example with different constraints on flask to test a
library with both versions using `tox <https://tox.readthedocs.io/en/latest/>`__:

.. code-block:: bash

    $ pip-compile --upgrade-package 'flask<1.0' --output-file requirements-flask0x.txt
    $ pip-compile --upgrade-package 'flask<2.0' --output-file requirements-flask1x.txt

Or to output to standard output, use ``--output-file=-``:

.. code-block:: bash

    $ pip-compile --output-file=- > requirements.txt
    $ pip-compile - --output-file=- < requirements.in > requirements.txt

Configuration
-------------

You might be wrapping the ``pip-compile`` command in another script. To avoid
confusing consumers of your custom script you can override the update command
generated at the top of requirements files by setting the
``CUSTOM_COMPILE_COMMAND`` environment variable.

.. code-block:: bash

    $ CUSTOM_COMPILE_COMMAND="./pipcompilewrapper" pip-compile requirements.in
    #
    # This file is autogenerated by pip-compile
    # To update, run:
    #
    #    ./pipcompilewrapper
    #
    flask==0.10.1
    itsdangerous==0.24        # via flask
    jinja2==2.7.3             # via flask
    markupsafe==0.23          # via jinja2
    werkzeug==0.10.4          # via flask

Example usage for ``pip-sync``
==============================

Now that you have a ``requirements.txt``, you can use ``pip-sync`` to update
your virtual environment to reflect exactly what's in there. This will
install/upgrade/uninstall everything necessary to match the
``requirements.txt`` contents.

Run it with ``pip-sync`` or ``python -m piptools sync``. If you use multiple
Python versions, you can also run ``py -X.Y -m piptools sync`` on Windows and
``pythonX.Y -m piptools sync`` on other systems.

**Be careful**: ``pip-sync`` is meant to be used only with a
``requirements.txt`` generated by ``pip-compile``.

.. code-block:: bash

    $ pip-sync
    Uninstalling flake8-2.4.1:
      Successfully uninstalled flake8-2.4.1
    Collecting click==4.1
      Downloading click-4.1-py2.py3-none-any.whl (62kB)
        100% |................................| 65kB 1.8MB/s
      Found existing installation: click 4.0
        Uninstalling click-4.0:
          Successfully uninstalled click-4.0
    Successfully installed click-4.1

To sync multiple ``*.txt`` dependency lists, just pass them in via command
line arguments, e.g.

.. code-block:: bash

    $ pip-sync dev-requirements.txt requirements.txt

Passing in empty arguments would cause it to default to ``requirements.txt``.

If you use multiple Python versions, you can run ``pip-sync`` as
``py -X.Y -m piptools sync ...`` on Windows and
``pythonX.Y -m piptools sync ...`` on other systems.

**Note**: ``pip-sync`` will not upgrade or uninstall packaging tools like
``setuptools``, ``pip``, or ``pip-tools`` itself. Use ``pip install --upgrade``
to upgrade those packages.

Other useful tools
==================

- `pipdeptree`_ to print the dependency tree of the installed packages.
- ``requirements.in``/``requirements.txt`` syntax highlighting:

  * `requirements.txt.vim`_ for Vim.
  * `Python extension for VS Code`_ for VS Code.

.. _pipdeptree: https://github.com/naiquevin/pipdeptree
.. _requirements.txt.vim: https://github.com/raimon49/requirements.txt.vim
.. _Python extension for VS Code: https://marketplace.visualstudio.com/items?itemName=ms-python.python