Fix app

app.py

@@ -237,9 +237,14 @@ if (st.session_state.uploaded):
   )
 
   if (forecast_button):
+    df_csv = df.to_csv()
+    df = pd.read_csv(df_csv, index_col = 'Date', parse_dates= True)
+    df = df.dropna()
+
     # Create the eXogenous values
     df['Sales First Difference'] = df['Sales'] - df['Sales'].shift(1)
     df['Seasonal First Difference'] = df['Sales'] - df['Sales'].shift(12)
+    df = df.dropna()
 
     auto_train_test = train_test(df, 20)
     training_y, test_y, test_y_series, training_X, test_X, future_X = auto_train_test