added onchange debug functor

app.py

@@ -35,6 +35,8 @@ with st.spinner("Loading Model"):
     
 select_idx = None
 
+def onchange():
+    st.write("this has changed")
 
 st.sidebar.title("Select a sample image")
 
@@ -44,7 +46,8 @@ if st.sidebar.button("Random Sample Image"):
 sample_image = st.sidebar.selectbox(
     "",
     sample_images,
-    index = 0 if select_idx is None else select_idx
+    index = 0 if select_idx is None else select_idx,
+    on_change=onchange
 )
 
 st.sidebar.title("Select a Subreddit")