SysEnv: the environment variable helper

Simple handling of system environment variables for application deployment.

SysEnv lets you configure your Python application using environment variables, casting types as necessary, enabling smooth 12factor deployments.

It’s a replacement for an inline function, with some inspiration and code from Honcho. The interface is directly inspired by Django-environ but unlike Django-environ SysEnv is not Django specific and does not replace functionality provided by existing applications.

• Free software: BSD license
• Documentation: http://sysenv.rtfd.org.

Installation

pip install sysenv

Using SysEnv

To load from your local environment, use the load function to return an EnvDict instance.:

>>> from sysenv import load
>>> env = load()

By default it loads from the system environment, but you can also include values from a .env or similar file.:

>>> from sysenv import load
>>> env = load('.env')

The EnvDict instance can be accessed like a normal Python dictionary.:

>>> env['DEBUG']
'True'
>>> env.get('DEBUG', False)
'True'

Of course your environment variables are strings, so you’ll want to cast the return value to a boolean.:

>>> env.get('DEBUG', False, cast=bool)
True

Alternatively you can define a schema when you initialize your EnvDict.:

>>> env = EnvDict(schema={'DEBUG': bool, 'CACHE_COUNT': int})
>>> env = load(schema={'DEBUG': bool, 'CACHE_COUNT': int})

The schema should be provided as a dictionary of key names with the cast identifier given as the value in the schema.

Using with Django

To use SysEnv in your Django project add it to the top of your settings.py file and pull in setting values from the env variable (or whatever you call it).:

from sysenv import load
env = load('.env')
DEBUG = env.get('DEBUG', False, cast=bool)

See the docs for additional usage instructions.