env4conf

Python library to override configuration entries with environment variables

Installation

To install this module via pip use

pip install git+https://github.com/iotec-gmbh/env4conf@v0.1

or for the latest version

pip install git+https://github.com/iotec-gmbh/env4conf

Usage

The simpliest way to use this module is to start with an empty configuration dictionary and fill ist from the environment.

>>> import os
>>> from env4conf import env2dict
>>> conf = {}
>>> os.environ["ENV2CONF_KEY"] = "value"
>>> env2dict(conf, prefix="ENV2CONF")
>>> print(conf)
{'key': 'value'}

You can also override variables.

>>> conf = {'key': 'old_value'}
>>> os.environ["ENV2CONF_KEY"] = "new_value"
>>> env2dict(conf, prefix="ENV2CONF")
>>> print(conf)
{'key': 'new_value'}

Or create lists in the configuration. But for that you need to initialize the variable as a list before so that env4conf knows how to treat it.

>>> conf = {"list": []}
>>> os.environ["ENV2CONF_LIST"] = "value1,value2,value3"
>>> env2dict(conf, prefix="ENV2CONF")
>>> print(conf)
{'list': ['value1', 'value2', 'value3']}

Same applies to nested dictionaries.

>>> conf = {"dict": {}}
>>> os.environ["ENV2CONF_DICT_KEY1"] = "value1"
>>> os.environ["ENV2CONF_DICT_KEY2"] = "value2"
>>> env2dict(conf, prefix="ENV2CONF")
>>> print(conf)
{'dict': {'key1': 'value1', 'key2': 'value2'}}

You can also use objects to store your configuration

>>> import os
>>> from env4conf import env2cls
>>> class Conf():
...     pass
... 
>>> conf = Conf()
>>> conf.key = "old_value"
>>> conf.list = []
>>> conf.dict = {}
>>> os.environ["ENV2CONF_KEY"] = "new_value"
>>> os.environ["ENV2CONF_LIST"] = "value1,value2,value3"
>>> os.environ["ENV2CONF_DICT_KEY1"] = "value1"
>>> os.environ["ENV2CONF_DICT_KEY2"] = "value2"
>>> env2cls(conf, prefix="ENV2CONF")
>>> print(conf)
<__main__.Conf object at 0x7f15ce6f92e8>
>>> print(conf.__dict__)
{'key': 'new_value', 'list': ['value1', 'value2', 'value3'], 'dict': {'key1': 'value1', 'key2': 'value2'}}