input: 
  def print_reverse_array(arr):
      """ Print out an array backwards."""
      for i in range(len(arr)-1, -1, -1): 
          print(arr[i])
  
  """
  Test Cases:
  >>> print_reverse_array([1, 2, 3, 4])
  4
  3
  2
  1
  >>> print_reverse_array(['a', 'b', 'c'])
  c
  b
  a
  """
output:     for i in range(len(arr)-1, -1, -1): 
          print(arr[i])