Using a dictionary as a repository

Now, we will create a MessageManager class that we will use to persist the MessageModel instances in an in-memory dictionary. Our API methods will call methods for the MessageManager class to retrieve, insert, update, and delete MessageModel instances. Create a new api.py file in the api folder. The following lines show the code that creates a MessageManager class in the api/api.py file. In addition, the following lines declare all the imports we will need for all the code we will write in this file. The code file for the sample is included in the restful_python_chapter_05_01 folder.

from flask import Flask 
from flask_restful import abort, Api, fields, marshal_with, reqparse, Resource 
from datetime import datetime 
from models import MessageModel 
import status 
from pytz import utc 
 
 
class MessageManager(): 
    last_id = 0 
    def __init__(self): 
        self.messages = {} 
 
    def insert_message(self, message): 
        self.__class__.last_id...