Django-Style "settings.py" Configuration

If you enjoy accessing global configuration via import statements ala Django's settings.py, you can do something similar in Pyramid.

• Create a settings.py file in your application's package (for example, if your application is named "myapp", put it in the filesystem directory named myapp; the one with an __init__.py in it.

• Add values to it at its top level.

For example:

# settings.py
import pytz

timezone = pytz('US/Eastern')

Then simply import the module into your application:

from myapp import settings

def myview(request):
    timezone = settings.timezone
    return Response(timezone.zone)

This is all you really need to do if you just want some global configuration values for your application.

However, more frequently, values in your settings.py file need to be conditionalized based on deployment settings. For example, the timezone above is different between development and deployment. In order to conditionalize the values in your settings.py you can use other values from the Pyramid development.ini or production.ini. To do so, your settings.py might instead do this:

import os

ini = os.environ['PYRAMID_SETTINGS']
config_file, section_name = ini.split('#', 1)

from paste.deploy.loadwsgi import appconfig
config = appconfig('config:%s' % config_file, section_name)

import pytz

timezone = pytz.timezone(config['timezone'])

The value of config in the above snippet will be a dictionary representing your application's development.ini configuration section. For example, for the above code to work, you'll need to add a timezone key/value pair to a section of your development.ini:

[app:myapp]
use = egg:MyApp
timezone = US/Eastern

If your settings.py is written like this, before starting Pyramid, ensure you have an OS environment value (akin to Django's DJANGO_SETTINGS) in this format:

export PYRAMID_SETTINGS=/place/to/development.ini#myapp

/place/to/development.ini is the full path to the ini file. myapp is the section name in the config file that represents your app (e.g. [app:myapp]). In the above example, your application will refuse to start without this environment variable being present.