Update app.py

app.py

@@ -114,7 +114,7 @@ def main():
     # Search button
     if st.button("Search"):
         #Ensure Dataset is selected
-        if st.session_state.df = None:
+        if 'df' not in st.session_state:
             st.warning("You have not selected a Dataset. Please click on Load Dataset to load your respective Dataset")
         # Validate input
         if not query: