def convert_to_string_only_dict(input_dict):
    """
    Convert all values of a dictionary to string objects
    Useful, if you want to save a dictionary as .json file to the disk

    :param input_dict: dict, input to be converted
    :return: dict, converted string dictionary
    """
    converted_dict = dict()
    for key, value in input_dict.items():
        if isinstance(value, dict):  # transform dictionaries recursively
            converted_dict[key] = convert_to_string_only_dict(value)
        elif isinstance(value, type):
            converted_dict[key] = str(value.__name__)
        else:
            converted_dict[key] = str(value)
    return converted_dict