Update app.py

app.py

@@ -86,7 +86,7 @@ def init_FD_seed_frame():
 @st.cache_data
 def convert_df(array):
     array = pd.DataFrame(array, columns=column_names)
-    return df.to_csv().encode('utf-8')
+    return array.to_csv().encode('utf-8')
 
 @st.cache_data
 def calculate_value_frequencies(np_array):