Fixed #19216 - Switched to user level installation in apps tutorial.

Since we moved the ``polls`` directory out of the project, it's no longer

working. We'll now fix this by installing our new ``django-polls`` package.

.. admonition:: Installing as a system library

.. admonition:: Installing as a user library

   The following steps install ``django-polls`` as a system library. In

   general, it's best to avoid messing with your system libraries to avoid

   breaking things. For this simple example though, the risk is low and it will

   help with understanding packaging. We'll explain how to uninstall in

   step 4.

   The following steps install ``django-polls`` as a user library. Per-user

   installs have a lot of advantages over installing the package system-wide,

   such as being usable on systems where you don't have administrator access

   as well as preventing the package from affecting system services and other

   users of the machine. Python 2.6 added support for user libraries, so if

   you are using an older version this won't work, but Django 1.5 requires

   Python 2.6 or newer anyway.

   For experienced users, a neater way to manage your packages is to use

   "virtualenv" (see below).

   Note that per-user installations can still affect the behavior of system

   tools that run as that user, so ``virtualenv`` is a more robust solution

   (see below).

1. Inside ``django-polls/dist``, untar the new package

   ``django-polls-0.1.tar.gz`` (e.g. ``tar xzvf django-polls-0.1.tar.gz``). If

2. Change into the directory created in step 1 (e.g. ``cd django-polls-0.1``).

3. If you're using GNU/Linux, Mac OS X or some other flavor of Unix, enter the

   command ``sudo python setup.py install`` at the shell prompt.  If you're

   using Windows, start up a command shell with administrator privileges and

   run the command ``setup.py install``.

   command ``python setup.py install --user`` at the shell prompt.  If you're

   using Windows, start up a command shell and run the command

   ``setup.py install --user``.

   With luck, your Django project should now work correctly again. Run the

   server again to confirm this.

4. To uninstall the package, use pip (you already :ref:`installed it

   <installing-reusable-apps-prerequisites>`, right?)::

    sudo pip uninstall django-polls

    pip uninstall django-polls

.. _bsdtar: http://gnuwin32.sourceforge.net/packages/bsdtar.htm

.. _7-zip: http://www.7-zip.org/

Installing Python packages with virtualenv

==========================================

Earlier, we installed the polls app as a system library. This has some

Earlier, we installed the polls app as a user library. This has some

disadvantages:

* Modifying the system libraries can affect other Python software on your

  system.

* Modifying the user libraries can affect other Python software on your system.

* You won't be able to run multiple versions of this package (or others with

  the same name).