Postgresql App for Mac

OSX users who develop Python applications (any application really) that
use PostgreSQL are in luck. If you are looking
for, quite possibly, the easiest way to install, run and use the most
advanced open source database on the planet
(provided you are using Mac OSX > 10.7).
Postgres.app - will make your life very
happy. When you just want to run PostgreSQL and get to coding,
Postgres.app from Matt Thompson and the awesome
people at Heroku is where its at.

Install PostgreSQL

1. Use Homebrew and follow this guide
   or something similar
2. Use the PostgreSQL binaries and follow this
   guide
3. Use postgres.app - it is hard to make an argument against this app.
   Download it, drag it to applications, DONE.

Use PostgreSQL

If you have ever used postgreSQL from the commandline you have
undoubtedly felt this pain:

:::bash
pg_ctl -D /usr/local/var/postgres start
pg_ctl -D /usr/local/var/postgres status
pg_ctl -D /usr/local/var/postgres stop -s -m fast

This is just to start and/or check on the darn thing. Then you can enter
the psql command to access the $USER database.
Remember that the $USER database doesn't have a user/password like
it would in a production environment.

Use Postgres.app

The postgres app simplifies this process by allowing you to start
PostgreSQL like any other mac app, click on the app.
But before you do that; Add one line to your .bashrc or in my case,
.zshrc.

PATH="/Applications/Postgres.app/Contents/MacOS/bin:$PATH"

Once the app initializes, you get the cool little elephant in your
toolbar. That's it, PostgreSQL is running and ready to
relation. With this done you can now create a database:

:::bash
$ psql
psql (9.2.2)
Type "help" for help.

$ michaelmartinez=# CREATE DATABASE my_database;
# If you want to delete the database you just created
$ michaelmartinez=# DROP DATABASE my_database;

note: don't forget the semi-colon!

Use for Development

To use this with Django you need to install the psycopg2 package, then
its just a matter of adding the correct parameters
to your DATABASE settings:

:::python
DATABASES = {
"default": {
"ENGINE": "django.db.backends.postgresql_psycopg2",
"NAME": "my_database",
"USER": "",
"PASSWORD": "",
"HOST": "localhost",
"PORT": "",
}
}

To use this with your Flask app, you can use the Flask-SQLAlchemy
extension or SQLAlchemy on its own:

:::python
from flask import Flask
from flask.ext.sqlalchemy import SQLAlchemy

app = Flask(name)
app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://localhost/my_database'
db = SQLAlchemy(app)

Vanilla SQLAlchemy

:::python
from sqlalchemy import create_engine
engine = create_engine('postgresql://localhost/my_database')