Update app.py

app.py

@@ -83,13 +83,17 @@ if submitted:
         except:
             selected_df = pd.DataFrame()
             pass
-    if len(selected_df) != 0 or selected_df != None:
-        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')
-
+    if selected_df != None:
+        if len(selected_df) != 0 or 
+            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')
+    
+        else:
+            st.success('Feature vector failed.')
     else:
         st.success('Feature vector failed.')
-    
+
+