src.config
==========

.. py:module:: src.config


Attributes
----------

.. autoapisummary::

   src.config.T


Functions
---------

.. autoapisummary::

   src.config.get_env_variable
   src.config._cast_str


Module Contents
---------------

.. py:data:: T

.. py:function:: get_env_variable(var_name: str, default: T = None, allow_empty: bool = False, cast_to: Type[T] = str) -> T

   Reads an environment variable, with settings to allow defaults, empty values, and type casting
   To read a boolean EXAMPLE_ENV_VAR=False use get_env_variable("EXAMPLE_ENV_VAR", cast_to=bool)

   :param var_name: The name of the environment variable to retrieve.
   :type var_name: str
   :param default: Default return value if the environment variable does not exist. Doesn't override empty string vars.
   :type default: T = None
   :param allow_empty: If False then a KeyError will be raised if the environment variable is empty.
   :type allow_empty: bool
   :param cast_to: The type to cast to e.g. str, int, or bool
   :type cast_to: Type[T]

   :rtype: The environment variable, or default if it does not exist, as type T.

   :raises KeyError: If allow_empty is False and the environment variable is empty string or None
   :raises ValueError: If cast_to is not compatible with the value stored.


.. py:function:: _cast_str(str_to_cast: str, cast_to: Type[T]) -> T

   Takes a string and casts it to necessary primitive builtin types. Tested with int, float, and bool.
   For bool, this detects if the value is in the case-insensitive sets {"True", "T", "1"} or {"False", "F", "0"}
   and raises a ValueError if not. For example _cast_str("False", bool) -> False

   :param str_to_cast: The string that is going to be casted to the type
   :type str_to_cast: str
   :param cast_to: The type to cast to e.g. bool
   :type cast_to: Type[T]

   :rtype: The string casted to type T defined by cast_to.

   :raises ValueError if [cast_to] is not compatible with the value stored.: