**********************
Playing with PL/Python
**********************
.. highlight:: bash

Prerequisites::

    sudo apt-get install postgresql-plpython-9.3
    # must be superuser to create procedural language "plpythonu"
    sudo -Hnu postgres psql -c "ALTER USER felix WITH SUPERUSER"
    sudo -Hnu postgres psql -c "CREATE EXTENSION plpythonu"
    # or for a certain DB:
    sudo -Hnu postgres psql $dbname -c "CREATE EXTENSION plpythonu"

.. highlight:: postgresql

Simple function that returns a table::

    CREATE FUNCTION store_foo()
        RETURNS TABLE (id int, name text)
    AS $$
        return (
            dict(id=i, name='foo-{0}'.format(i))
            for i in range(1000)
        )
    $$ LANGUAGE plpythonu;

    select * from store_foo();

Importing modules from anywhere at runtime
==========================================
The cleaner solution would be to set PYTHONPATH for the postgresql server
process.

.. highlight:: bash

Example module::

    mkdir -p /tmp/foo
    cat <<EOF > /tmp/foo/foo.py
    def f():
        return 'hello from foo'
    EOF

.. highlight:: postgresql

Function::

    CREATE FUNCTION foo_module()
        RETURNS text
    AS $$
        import sys
        sys.path.insert(0, '/tmp/foo')
        import foo
        return foo.f()
    $$ LANGUAGE plpythonu;

    select foo_module();

Multicorn
=========
http://multicorn.org/

.. highlight:: bash

Prerequisites::

    sudo apt-get install postgresql-server-dev-9.3
    sudo pip install pgxnclient
    sudo pgxn install multicorn