Python Config

config.py

import json
import os
from pathlib import Path
from typing import Optional

DEFAULT_CONFIG_NAME = "default.json"
SECRETS_FILE_PATH = "secrets.json"


class Config(object):
    """
    Your one stop solution for path based configuration files.
    Loads stuff via JSON. Has commodity functions. 
    """
    def __init__(self, config_path_str: str or None = None):
        if config_path_str is None or config_path_str == '':
            config_path = Path(os.path.join(os.path.dirname(__file__), 'conf', DEFAULT_CONFIG_NAME))
        else:
            config_path = Path(config_path_str)
            if not config_path.exists():
                raise Exception(f"Config path was passed, but file is unreachable at '{config_path.absolute()}' ")
        with open(str(config_path), 'r') as file:
            self._config: dict = json.load(file)

        secrets_path_str = self.get_property('application.secrets_path')
        if secrets_path_str is None or secrets_path_str == '':
            secrets_path = Path(os.path.join(os.path.dirname(__file__), 'conf', SECRETS_FILE_PATH))
        else:
            secrets_path = Path(secrets_path_str)
        with open(str(secrets_path), 'r') as file:
            self._config['secrets'] = json.load(file)

    def _find(self, path: str, dictionary: dict) -> Optional[any]:
        keys = path.split('.')
        current_value: any = dictionary
        for key in keys:
            if key not in current_value:
                return None
            current_value = current_value[key]
        return current_value

    def get_property(self, property_path: str) -> Optional[any]:
        """
        Returns the property or None
        :param property_path:
        :return:
        """
        return self._find(property_path, self._config)

    def get_property_or_raise(self, property_path: str, message: str = None) -> any:
        """
        Returns a property or raises an exception
        :param property_path:
        :param message:
        :return:
        """
        value = self._find(property_path, self._config)
        if value is None:
            if message is None:
                message = f"value for path {property_path} not found in config"
            raise Exception(message)
        return value

    def get_property_or_default(self, property_path: str, default: any) -> any:
        """
        Returns the property or a default value
        :param property_path:
        :param default:
        :return:
        """
        value = self._find(property_path, self._config)
        if value is None:
            return default
        return value

    def override_property(self, property_path: str, new_value: any):
        """
        Overrides a property in the config
        :param property_path:
        :param new_value:
        :return:
        """
        keys = property_path.split('.')
        value: any = self._config
        for (index, key) in enumerate(keys, start=0):
            if index < len(keys) - 1:
                if key not in value:
                    value[key] = {}
                else:
                    value = value[key]
            else:
                value[key] = new_value
        return value