Update app.py

app.py

@@ -83,9 +83,13 @@ if submitted:
         except:
             selected_df = pd.DataFrame()
             pass
-    st.success('Feature vector successfully created.')
-    csv = convert_df(selected_df)
+    if len(selected_df) != 0:
+        st.success('Feature vector successfully created.')
+        csv = convert_df(selected_df)
 
-    st.download_button("Press to Download the Feature Vector", csv,"ASCARIS_SAV_rep.csv","text/csv",key='download-csv')
+        st.download_button("Press to Download the Feature Vector", csv,"ASCARIS_SAV_rep.csv","text/csv",key='download-csv')
 
+    else:
+        st.success('Feature vector failed.')
+