Environment to python dictionary parser util
- About
- Syntax
- Examples
- How to use
- More info

Environment to python dictionary parser util

pip install env2dict

About

This small package provides an ability of easy setting/overriding Python variables from environment. It is expected that u will use it to override your configuration data without changing configuration files itself, what is especially useful for containers-oriented applications.

Syntax

To use it, u need to define environment variables matches the pattern: PrefixBodyOperationSuffix where:

Prefix is any word to determine target variables; for instance, DD prefix means to use only variables starts with DD; can be empty, what means to select all available variables (not recommended)
Body is the name of the target configuration parameter
OperationSuffix is the one of next available suffixes (by default, but u can change your defaults):
- _NUMBER to convert variable value to integer (environment variables are always strings)
- _FLOAT to convert variable value to float
- _FLAG to convert variable value to optional[boolean] at that values:
  - 1/yes/Yes/True/true equal true
  - 0/no/No/False/false equal false
  - None/null/NULL equal null
- _LIST means to parse variable value to string list
- _LIST_APPEND means to parse variable value to string list and append to existing list instead of override
- _JSON means to parse variable value as json string
- no suffix means that no conversion will be performed, so variable value will stay a string

Moreover, u can put nested dicts values using __ separator (or other on your choice) in the environment variable name.

Note also that u can combine these suffixes to perform more complicated transformations.

Examples

env variable DD_S_COUNT_NUMBER=10 (with prefix DD_ conversation) will be converted to S_COUNT=10 Python object
DD_S_COUNT=10 🠚 S_COUNT="10"
DD_USE_THIS_FLAG=yes 🠚 USE_THIS=True
DD_USE_THIS_FLAG=true 🠚 USE_THIS=True
DD_USE_THIS_FLAG=no 🠚 USE_THIS=False
DD_ALLOWED_HOSTS_LIST_APPEND=127.0.0.1;dev.ocr.com;dev.web.com will append a list ['127.0.0.1', 'dev.ocr.com', 'dev.web.com'] to ALLOWED_HOSTS variable
DD_READ_ME_JSON={\"a\": 1, \"b\": [1, 2]} will be translated to READ_ME={'a': 1, 'b': [1, 2]}
DD_SOME_DICT__KEY1__KEY2=postgres will create a dictionary SOME_DICT={'KEY1': {'KEY2': 'postgres'}} if it doesn't exist and will add a field in existing dictionary by aforementioned route
DD_A__B_LIST_APPEND_JSON=[1, 2, 3, [1, 2, \"3\"]] will append [1, 2, 3, [1, 2, "3"]] to the end of value V from A={"B": V}

How to use

from env2dict import parse_vars

new_vars = parse_vars(
    prefix='DD_',
    initial_vars=None,
    source=None
)

More info

Please take a look at: