src.config

Attributes

T

Functions

get_env_variable(→ T)

Reads an environment variable, with settings to allow defaults, empty values, and type casting

_cast_str(→ T)

Takes a string and casts it to necessary primitive builtin types. Tested with int, float, and bool.

Module Contents

src.config.T
src.config.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)

Parameters:

  • var_name (str) – The name of the environment variable to retrieve.

  • default (T = None) – Default return value if the environment variable does not exist. Doesn’t override empty string vars.

  • allow_empty (bool) – If False then a KeyError will be raised if the environment variable is empty.

  • cast_to (Type[T]) – The type to cast to e.g. str, int, or bool

Return type:

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

  • ValueError – If cast_to is not compatible with the value stored.

src.config._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

Parameters:

  • str_to_cast (str) – The string that is going to be casted to the type

  • cast_to (Type[T]) – The type to cast to e.g. bool

Return type:

The string casted to type T defined by cast_to.

Raises:

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