Update app.py

updated the code to handle no pdf file provided

app.py

@@ -73,20 +73,27 @@ def split_text(text, chunk_size=500):
 def chatbot(pdf_file, user_question):
     """Processes the PDF and answers the user's question."""
     print("chatbot start")
-    
-    # Extract text from the PDF
-    text = extract_text_from_pdf(pdf_file)
-    if not text:
-        return "Could not extract any text from the PDF."
-
-    # retrieve the document relevant to the query
-    doc = retrieve_document(user_question)
 
-    # Split into smaller chunks
-    chunks = split_text(doc)
+    if pdf_file:
+        # Extract text from the PDF
+        text = extract_text_from_pdf(pdf_file)
+        if not text:
+            return "Could not extract any text from the PDF."
 
-    # Use only the first chunk (to optimize token usage)
-    prompt = f"Based on this document, answer the question:\n\nDocument:\n{chunks[0]}\n\nQuestion: {user_question}"
+    try:
+        # retrieve the document relevant to the query
+        doc = retrieve_document(user_question)           
+    except Exception as e:
+        return f"Error retrieving document relevant to the query: {user_question} \n{e}"
+
+    if doc:
+        # Split into smaller chunks
+        chunks = split_text(doc)
+      
+        # Use only the first chunk (to optimize token usage)
+        prompt = f"Based on this document, answer the question:\n\nDocument:\n{chunks[0]}\n\nQuestion: {user_question}"
+    else:
+              prompt=user_question
 
     try:
             response = together.Completion.create(