== Using virtualenv

It's always a good idea to use virtualenv to develop python software.

1. Install pip, virtualenv (python-pip, python-virtualenv packages)

   Because we're going to recompile our dependencies, we'll also need
   development headers:

   - For the MySQL/MariaDB setups: mariadb-devel (Fedora)

2. Create a new virtual environement. Virtual environments are "instances" of
   your system python, without any of the extra python packages installed.
   Inside a virtual env, we'll just install the dependencies needed for
   patchwork and run it from there.

   Virtual envs are useful to develop and deploy patchwork against a "well
   known" set of dependencies. They can also be used to test patchwork against
   several versions of django, creating a separate virtual env per version.

   $ virtualenv django-1.7

   will create a virtual env called 'django-1.7' in eponymous directory.

3. Activate a virtual environment

   $ sources django-1.7/bin/activate
   (django-1.7)$

   The shell prompt is preprended with the virtual env name.

4. Install the required dependencies

   To ease this task, it's customary to maintain a list of dependencies in a
   text file and install them in one go. One can maintain such a list of
   dependencies per interesting configuration.

   (django-1.7)$ pip install -r docs/requirements-django-1.7-mysql.txt

   Of course, this is a one-time step, once installed in the virtual
   environment, no need to to install the requirements everytime.

5. Now one can run patchwork within that environment

   (django-1.7)$ ./apps/manage.py --version
   1.7
   (django-1.7)$ ./apps/manage.py runserver

6. To exit the virtual environment

   (django-1.7)$ deactivate
   $