def _incorrect_data_type_message(
    data_dict: dict, field_name: str, expected_type: str
) -> str:
    """
    Creates a string explaining to the user that the field input did not have the expected type.
    :param data_dict: The dictionary containing the different data fields for the disk chopper.
    :param field_name: The name of the field that failed the check.
    :param expected_type: The expected data type.
    :return: A string that contains the name of the field, the type it should have, and the type the user entered.
    """
    return (
        f"Wrong {field_name} type. Expected {expected_type} but found"
        f" {data_dict[field_name].dtype}."
    )