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

*If you would like to contribute to Wallace, please follow these
:doc:`alternative install
instructions <developing_wallace_setup_guide>`.*

Install Python
^^^^^^^^^^^^^^

Wallace is written in the language Python. For it to work, you will need
to have Python 2.7 installed. You can check what version of Python you
have by running:

::

    python --version

If you do not have Python 2.7 installed, you can install it from the
`Python website <https://www.python.org/downloads/>`__.

Install Postgres
^^^^^^^^^^^^^^^^

Wallace uses Postgres to create local databases. On OS X, install
Postgres from `postgresapp.com <http://postgresapp.com>`__. This will
require downloading a zip file, unzipping the file and installing the
unzipped application.

You will then need to add Postgres to your PATH environmental variable.
If you use the default location for installing applications on OS X
(namely ``/Applications``), you can adjust your path by running the
following command:

::

    export PATH="/Applications/Postgres.app/Contents/Versions/9.3/bin:$PATH"

NB: If you have installed a more recent version of Postgres (e.g., the
`the upcoming version
9.4 <https://github.com/PostgresApp/PostgresApp/releases/tag/9.4rc1>`__),
you may need to alter that command slightly to accommodate the more
recent version number. To double check which version to include, then
run:

::

    ls /Applications/Postgres.app/Contents/Versions/

Whatever number that returns is the version number that you should place
in the ``export`` command above. If it does not return a number, you
have not installed Postgres correctly in your ``/Applications`` folder
or something else is horribly wrong.

Create the Database
^^^^^^^^^^^^^^^^^^^

After installing Postgres, you will need to create a database for your
experiments to use. Run the following command from the command line:

::

    psql -c 'create database wallace;' -U postgres

Install Wallace
^^^^^^^^^^^^^^^

Install Wallace from the terminal by running

::

    pip install wallace-platform

Test that your installation works by running:

::

    wallace --version

If you use Anaconda, installing Wallace probably failed. The problem is
that you need to install bindings for the ``psycopg2`` package (it helps
Python play nicely with Postgres) and you must use conda for conda to
know where to look for the links. You do this with:

::

    conda install psycopg2

Then, try the above installation commands. They should work now, meaning
you can move on.

Next, you'll need :doc:`access keys for AWS, Heroku,
etc. <aws_etc_keys>`.