Update app.py

app.py

@@ -42,10 +42,12 @@ for message in st.session_state.messages:
     else:
         st.write(f"**Physics Master:** {message['content']}")
 
-# Input for user to ask questions
-user_input = st.text_input("Ask a question", key="user_input")
+# Use a form to manage user input and submission
+with st.form(key="input_form", clear_on_submit=True):
+    user_input = st.text_input("Ask a question", key="user_input")
+    submit_button = st.form_submit_button(label="Send")
 
-if user_input:
+if submit_button and user_input:
     # Append user message
     user_message = {'role': 'user', 'content': user_input}
     st.session_state.messages.append(user_message)
@@ -77,9 +79,6 @@ if user_input:
     # Display the full response as a paragraph
     st.write(f"**Physics Master:** {full_response}")
 
-    # Reset user input box
-    st.session_state.user_input = ""
-
 # Save the chat history to a JSON file
 with open('chat_history.json', 'w', encoding='utf8') as file:
     json.dump(st.session_state.messages, file, indent=4)