input: Write a python function to check if a list is a palindrome.
  assert is_palindrome([1, 2, 3, 2, 1]) == True
  assert is_palindrome([1, 2, 3, 4, 5]) == False
  assert is_palindrome(['a', 'b', 'b', 'a']) == True
output: def is_palindrome(lst):
      return lst == lst[::-1]