Update app.py

app.py

@@ -285,8 +285,12 @@ with tab2:
             st.error("Please enter a question.")
 
     #generate the answer based on selected news content using the given model
-    df1 = pd.read_csv(uploaded_file)
     
+    if uploaded_file is None:
+        pass
+    else:
+        df1 = pd.read_csv(uploaded_file
+       
     st.markdown("---")
     st.header("Ask Questions Based on Your News Content")
     context_1 = st.selectbox("Choose an article for the question:", df1['content'].tolist())