Update app.py

app.py

@@ -246,6 +246,7 @@ def process_dataframe(df):
         
         # Create two DataFrames: one for prediction and one for classification.
         df_pred = df[required_columns].copy()
+        df_pred[['EngBlk', 'EngWht', 'EngOpen', 'EngPav']]=df_pred[['EngBlk', 'EngWht', 'EngOpen', 'EngPav']].fillna("NA")
         df_class = df[required_columns_2].fillna("NA").copy()
         
         # Transform categorical columns for prediction DataFrame using the label encoders.