. list_extender([1, 2, 3, 4]) returned None, did you remember to return the result?
i dont understand why does it show up this error.please help.
when n is passed as the argument it should append 9 to it and simply return the appended list properly.isnt it as simple as that?
n = [3, 5, 7] # Add your function here def list_extender(lst): return lst.append(9) print list_extender(n)