Update app.py

app.py

@@ -82,7 +82,7 @@ def main():
 
     st.write("### Total Estimated Monthly Units Consumed:", f"{total_units:.2f} kWh")
 
-    # Calculate the bill
+    # Ensure tariff data is fetched before bill calculation
     if st.button("Calculate Bill"):
         if 'tariff_data' in st.session_state and st.session_state['tariff_data']:
             bill = calculate_bill(total_units, st.session_state['tariff_data'])
@@ -91,7 +91,7 @@ def main():
             else:
                 st.error("Could not calculate the bill. Please check the tariff data.")
         else:
-            st.error("Please fetch the tariff rates first.")
+            st.error("Please fetch the tariff rates first using the 'Fetch Tariff Rates' button.")
 
 if __name__ == "__main__":
     # Initialize session state to store tariff data