Room-based messaging in Flask - Mini Project: Build & Apply

Room-based messaging

📖 Scenario: You are building a simple chat application where users can join different chat rooms and send messages visible only to that room.

🎯 Goal: Create a Flask app that supports multiple chat rooms. Users can join a room and send messages that only appear in that room.

📋 What You'll Learn

Create a dictionary to hold chat rooms and their messages

Add a variable to track the current room

Write a function to add messages to the current room

Complete the Flask route to display messages for the current room

💡 Why This Matters

🌍 Real World

Chat apps often separate conversations into rooms or channels so users can join topics they like.

💼 Career

Understanding how to manage data for different user groups and display dynamic content is key for web developers.

1

Create the chat rooms data structure

Create a dictionary called chat_rooms with these exact keys and values: 'general': [], 'sports': [], 'music': [].

Flask

# Create the chat_rooms dictionary with keys 'general', 'sports', and 'music' each set to an empty list
# Your code here

Need a hint?

Use curly braces to create a dictionary. Each key is a room name and the value is an empty list for messages.

2

Add current room variable

Add a variable called current_room and set it to the string 'general'.

Flask

chat_rooms = {'general': [], 'sports': [], 'music': []}
# Set current_room to 'general'
# Your code here

Need a hint?

Just assign the string 'general' to the variable current_room.

3

Write function to add messages

Write a function called add_message that takes a parameter message and appends it to the list in chat_rooms[current_room].

Flask

chat_rooms = {'general': [], 'sports': [], 'music': []}
current_room = 'general'

# Define add_message(message) to add message to chat_rooms[current_room]
# Your code here

Need a hint?

Use the append() method on the list for the current room.

4

Complete Flask route to show messages

Complete the Flask route function called show_room that returns a string joining all messages in chat_rooms[current_room] separated by commas.

Flask

chat_rooms = {'general': [], 'sports': [], 'music': []}
current_room = 'general'

def add_message(message):
    chat_rooms[current_room].append(message)

from flask import Flask
app = Flask(__name__)

@app.route('/')
def show_room():
    # Return all messages in chat_rooms[current_room] joined by commas
    # Your code here

Need a hint?

Use the join() method on the list of messages for the current room.