input: 
  def print_number_pattern():
      """ Print the following output pattern:
      1
      12
      123
      1234
      12345
      >>> print_number_pattern()
      1
      12
      123
      1234
      12345
      """
  
output:     for i in range(1, 6):
          print(''.join(str(x) for x in range(1, i + 1)))