config#

Functions for handling configuration files and environment variables.

Functions#

`try_get_val_from_dict`(→ tuple[str, str])	Attempt to get a configuration value from
`try_get_val_from_env`(→ tuple[str, str])	Attempt to get a configuration value from
`get_config_val`(→ str)	Get a configuration variable from

Module Contents#

try_get_val_from_dict(key: str, config_dict: dict, value_name: str = None) → tuple[str, str]#

Attempt to get a configuration value from a configuration dictionary. Return None along with an informative failure message if this is not possible.

Parameters#

key: Key under which to look up the value in the config_dict.
config_dict: Dictionary of configuration keys and values in which to look up the value.
value_name: Descriptive name for the configuration value, to allow more readable failure messages when the key cannot be found in config_dict. If None, use the value of key. Default None.

Returns#

tuple[str, str]: A tuple. Its first entry is the value if it was successfully retrieved and otherwise None. Its second entry is None on success and otherwise a description of the failure, as a string.

try_get_val_from_env(env_variable_name: str, value_name: str = None) → tuple[str, str]#

Attempt to get a configuration value from local environment variables. Return None along with an informative failure message if this is not possible.

Parameters#

env_variable_name: Name of the environment variable to attempt to retrieve.
value_name: Descriptive name for the value, for more readable failure messages when the env_variable_name cannot be located. If None, use the value of env_variable_name. Default None.

Returns#

tuple[str, str]: A tuple. Its first entry is the value of the variable if it was successfully retrieved and otherwise None. Its second entry is None on success and otherwise a description of the failure, as a string.

get_config_val(key: str, config_dict: dict = None, try_env: bool = True, env_variable_name: str = None, value_name: str = None) → str#

Get a configuration variable from a configuration dictionary and/or from local environment variables.

First consult a configuration dictionary, if one has been provided. Then consult environment variables if directed to do so. If no valid value can be found, raise a ValueError.

Parameters#

key: Key under which to look up the value in the config_dict, if one is provided, and variable name to check in the environment variables, if a distinct env_variable_name is not provided.
config_dict: Dictionary of configuration keys and values in which to look up the value. If None, only look in environment variables, provided try_env is True.
try_env: Look for the value in the environment variables if it cannot be found in the config_dict? Default True. If True, with look for an environment variable corresponding to key, but with that string converted to uppercase, (i.e. the output of key.upper()), unless a custom name is provided via the env_variable_name argument.
env_variable_name: Environmental variable name to check for the variable, if it cannot be found in the config. If None and try_env is True, use the value of key.upper().
value_name: Descriptive name for the configuration value, to produce more informative error messages when a valid value cannot be found. If None, use the value of key. Default None.

Returns#

str: The configuration value.

Raises#

ValueError: If the value cannot be found either in the configuration dictionary or in an environment variable, or if config_dict is None and try_env is False