input: Write a function to print a random element from a given list. The function should take in a list of elements and return a string that indicates the randomly selected element.
  assert print_random_element(["apple", "banana", "mango", "pear", "grape"])==None
  assert print_random_element(["apple", "banana", "mango", "pear", "grape"])==None
  assert print_random_element(["apple", "banana", "mango", "pear", "grape"])==None
  assert print_random_element(["apple", "banana", "mango", "pear", "grape"])==None
  assert print_random_element([])==None
output: import random
  
  def print_random_element(elements):
      if elements:
          return random.choice(elements)
      return None