banging my head on Streamlit

app.py

@@ -12,6 +12,26 @@ if 'child' not in st.session_state:
 
 child = st.session_state['child']
 
+# creating a single-element container
+placeholder = st.empty()
+
+
+while True:
+    time.sleep(1)
+    with placeholder.container():
+        # Display the list of messages
+        for msg in st.session_state['messages']:
+            st.write(msg)
+
+        st.session_state['messages'].append("Tick.")
+        line = child.readline()
+        st.session_state['messages'].append(line)
+        #if ">>>>>" in line: child.sendline(input(">>>>>"))
+
+
+
+
+"""
 last_line = child.readline()
 
 st.session_state['messages'].append(last_line)
@@ -29,7 +49,7 @@ if ">>>>>" in last_line:
         st.session_state['messages'].append(user_input)
         child.sendline(user_input)
 
-
+"""