Update app.py

app.py

@@ -93,8 +93,8 @@ def respond(user_text, chat_history, messages):
         }
     )
 
-    # update UI chat history
-    chat_history = chat_history + [(user_text, assistant_text)]
+    # update UI chat history (tuple format)
+    chat_history = (chat_history or []) + [(user_text, assistant_text)]
 
     return "", chat_history, messages
 
@@ -122,10 +122,8 @@ def clear_all():
 LOGO_URL = "https://raw.githubusercontent.com/Decoding-Data-Science/nov25/main/logo_python.png"
 
 css = """
-/* Overall spacing + subtle polish */
 #app_container {max-width: 1200px; margin: 0 auto;}
 
-/* Header styling */
 .header-wrap {
     display: flex;
     align-items: center;
@@ -143,14 +141,12 @@ css = """
     margin-top: 2px;
 }
 
-/* FAQ card-like feel */
 .faq-box {
     border: 1px solid rgba(255,255,255,0.08);
     border-radius: 12px;
     padding: 14px;
 }
 
-/* Make buttons full width in FAQ column */
 .faq-btn button {
     width: 100%;
     justify-content: flex-start;
@@ -185,12 +181,10 @@ with gr.Blocks(elem_id="app_container") as demo:
 
     gr.Markdown("---")
 
-    # State
     state = gr.State(init_messages())
 
-    # Two-column layout
     with gr.Row(equal_height=True):
-        # LEFT: FAQ + Quick Ask
+        # LEFT
         with gr.Column(scale=4, min_width=320):
             with gr.Group(elem_classes=["faq-box"]):
                 gr.Markdown("### FAQ — Most Asked Python Questions")
@@ -214,11 +208,12 @@ with gr.Blocks(elem_id="app_container") as demo:
                     value=None
                 )
 
-        # RIGHT: Chat area
+        # RIGHT
         with gr.Column(scale=8, min_width=520):
             chatbot = gr.Chatbot(
                 height=520,
-                label="Conversation"
+                label="Conversation",
+                type="tuples"   # ✅ IMPORTANT FIX
             )
 
             with gr.Row():
@@ -235,15 +230,10 @@ with gr.Blocks(elem_id="app_container") as demo:
                     "<span style='opacity:0.7;font-size:12px;'>Context is preserved across turns unless you clear.</span>"
                 )
 
-    # FAQ button -> fill textbox
+    # FAQ -> fill textbox
     for b, q in zip(faq_buttons, FAQ_QUESTIONS):
-        b.click(
-            fn=lambda q=q: set_question(q),
-            inputs=None,
-            outputs=msg
-        )
+        b.click(fn=lambda q=q: set_question(q), inputs=None, outputs=msg)
 
-    # Optional quick preference: append hint to textbox (UI-only)
     def apply_quick_pref(pref, current_text):
         if not pref:
             return current_text
@@ -251,31 +241,12 @@ with gr.Blocks(elem_id="app_container") as demo:
             return f"{current_text.strip()} ({pref})"
         return pref
 
-    quick.change(
-        fn=apply_quick_pref,
-        inputs=[quick, msg],
-        outputs=msg
-    )
+    quick.change(fn=apply_quick_pref, inputs=[quick, msg], outputs=msg)
 
-    # Submit logic
-    msg.submit(
-        respond,
-        inputs=[msg, chatbot, state],
-        outputs=[msg, chatbot, state]
-    )
+    msg.submit(respond, inputs=[msg, chatbot, state], outputs=[msg, chatbot, state])
+    send.click(respond, inputs=[msg, chatbot, state], outputs=[msg, chatbot, state])
 
-    send.click(
-        respond,
-        inputs=[msg, chatbot, state],
-        outputs=[msg, chatbot, state]
-    )
-
-    # Clear
-    clear.click(
-        fn=clear_all,
-        inputs=None,
-        outputs=[chatbot, state, msg]
-    )
+    clear.click(fn=clear_all, inputs=None, outputs=[chatbot, state, msg])
 
 demo.launch(
     debug=False,