It asks to append 9 to the list by calling the list_extender method. Even though 9 is getting appended to the list in the correct way, it still throws the error of not returning the list. I also tried storing the result in the 'lst' and then return lst separately. That too did not work.
As per the code written:
9 should be appended to the list
n = [3, 5, 7] # Add your function here def list_extender(lst): return lst.append(9) print list_extender(n) Instead i get the mentioned error: Oops, try again. list_extender([1, 2, 3, 4]) returned None, did you remember to return the result?