def get_value(obj, key, default_value):
    """
    :param obj: dictionary
    :param key: key
    :param default_value:  return default value if obj[key] is not existed.
    :return:  the value of an argument. If no such an argument, return a default value
    """
    return obj[key] if type(obj) is dict and key in obj.keys() and obj[key] != '' and obj[key] is not None else default_value