• 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:

• parse_vars function docstring
• tests directory of this package repo.