Update app.py

app.py

@@ -5,6 +5,7 @@ from langchain.callbacks.streaming_stdout import StreamingStdOutCallbackHandler
 from langchain.schema import StrOutputParser
 
 from custom_llm import CustomLLM, custom_chain_with_history, custom_combined_chain, custom_dataframe_chain, format_df,custom_unique_df_chain
+import pandas as pd
 
 
 API_TOKEN = os.getenv('HF_INFER_API')