Update app.py

app.py

@@ -5,7 +5,7 @@ from collections import defaultdict
 
 # Store all conversations and users
 conversations = defaultdict(list)
-usernames = {}
+usernames = defaultdict(list)
 
 # Generate a random conversation ID
 def generate_conversation_id():
@@ -14,12 +14,11 @@ def generate_conversation_id():
 # Handle new chat creation
 def new_chat():
     conversation_id = generate_conversation_id()
+    conversations[conversation_id] = []  # Initialize the conversation in the dictionary
     return conversation_id
 
 # Handle user joining the conversation
 def join_chat(chat_id, username):
-    if chat_id not in usernames:
-        usernames[chat_id] = []
     if username not in usernames[chat_id]:
         usernames[chat_id].append(username)
     return f"Welcome {username}! You have joined the chat."