from keystone's doc/source/setup.rst


PyPi Packages and VirtualEnv
----------------------------

We recommend establishing a virtualenv to run keystone within. Virtualenv
limits the python environment to just what you're installing as depdendencies,
useful to keep a clean environment for working on Keystone. The tools directory
in keystone has a script already created to make this very simple::

    $ python tools/install_venv.py

This will create a local virtual environment in the directory ``.venv``.
Once created, you can activate this virtualenv for your current shell using::

    $ source .venv/bin/activate

The virtual environment can be disabled using the command::

    $ deactivate

You can also use ``tools\with_venv.sh`` to prefix commands so that they run
within the virtual environment. For more information on virtual environments,
see virtualenv_.

.. _virtualenv: http://www.virtualenv.org/

If you want to run keystone outside of a virtualenv, you can install the
dependencies directly into your system from the requires files::

    # Install the dependencies for running keystone
    $ pip install -r tools/pip-requires

    # Install the dependencies for developing, testing, and running keystone
    $ pip install -r tools/test-requires

    # Use python setup.py to link Keystone into python's site-packages
    $ python setup.py develop