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?

Installation

$ pip install --upgrade pip  # pip-tools needs pip==8.0 or higher (!)
$ pip install pip-tools

Example usage for pip-compile

Suppose you have a Flask project, and want to pin it for production. Write the following line to a file:

# requirements.in
Flask

Now, run pip-compile requirements.in:

$ pip-compile requirements.in
#
# This file is autogenerated by pip-compile
# Make changes in requirements.in, then run this to update:
#
#    pip-compile requirements.in
#
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

And it will produce your requirements.txt, with all the Flask dependencies (and all underlying dependencies) pinned. Put this file under version control as well.

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:

$ 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

Example usage for pip-sync

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

$ 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.:

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

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