Update app.py

app.py

@@ -28,7 +28,7 @@ if uploaded_file is not None:
     with open(file_path, "wb") as f:  
         f.write(uploaded_file.getbuffer())  
     st.success(f"{selected_course}.csv File uploaded successfully")  
-
+present_students = []
 # Take Attendance  
 st.subheader("Record Attendance")  
 attendance_date = st.date_input("Select Date")