Now, we will create a simple MessageModel class that we will use to represent messages. Remember that we won't be persisting the model in the database, and therefore, in this case, our class will just provide the required attributes and no mapping information. Create a new models.py file in the api folder. The following lines show the code that creates a MessageModel class in the api/models.py file. The code file for the sample is included in the restful_python_chapter_05_01 folder:

class MessageModel: 
    def __init__(self, message, duration, creation_date, message_category): 
        # We will automatically generate the new id 
        self.id = 0 
        self.message = message 
        self.duration = duration 
        self.creation_date = creation_date 
        self.message_category = message_category 
        self.printed_times = 0 
        self.printed_once = False 

The MessageModel class just declares a constructor, that is, the __init__ method. This method receives many arguments and then uses them to initialize the attributes with the same names: message, duration, creation_date, and message_category. The id attribute is set to 0, printed_times is set to 0, and printed_once is set to False. We will automatically increment the identifier for each new message generated with API calls.