Update app.py

app.py

@@ -738,7 +738,7 @@ with tab3:
                 working_data1 = working_data[plot_var1].rolling('10D').mean()
                 working_data2 = working_data[plot_var2].rolling('10D').mean()
                 join_list = [working_data1, working_data2]
-                working_data - pd.concat(join_list, join='outer', axis=1)
+                working_data = pd.concat(join_list, join='outer', axis=1)
                 working_data = working_data.reset_index()
             elif plot_count == "Three":
                 working_data['Date'] = pd.to_datetime(working_data['Date'])
@@ -747,7 +747,7 @@ with tab3:
                 working_data2 = working_data[plot_var2].rolling('10D').mean()
                 working_data3 = working_data[plot_var3].rolling('10D').mean()
                 join_list = [working_data1, working_data2, working_data3]
-                working_data - pd.concat(join_list, join='outer', axis=1)
+                working_data = pd.concat(join_list, join='outer', axis=1)
                 working_data = working_data.reset_index()
         else:
             working_data = working_data