Basics🔗

Environments are defined with a simple class-based configuration in the settings.py module.

1
2
3
4

from env_config import Environment

class Example(Environment):
    DEBUG = True

The Environment must be selected by setting the DJANGO_SETTINGS_ENVIRONMENT environment variable to the name of the class. If the environment variable is not set, an exception will be raised, since the library will not be able to determine which environment should be used.

1

DJANGO_SETTINGS_ENVIRONMENT=Example python manage.py runserver

Similarly to the django-configurations library, the selected Environment's upper-case class attributes will be added as the module level global variables in the module where the environment is defined. This happens immidiately after the Environment class is defined as part of the class creation process.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12

from env_config import Environment

class Example(Environment):
    DEBUG = True

    # These will not be used
    not_global = None
    _NOT_GLOBAL = None

# Exists immidiately after Example is defined,
# given `DJANGO_SETTINGS_ENVIRONMENT=Example`
print(DEBUG)

However, this library's implementation is much simpler and doesn't require any additional configuration or setup. Here is the magic behind the scenes from env_config.base.Environment.setup:

1
2
3
4
5

# Inspect the call stack to find the module where the environment is defined
stack = inspect.stack()
module_globals = stack[stack_level].frame.f_globals
# Update the module's global variables with the environment's loaded settings
module_globals.update(**settings)

Of course, one should be a little careful that this does not override any existing global variables in the module.