input: 
  def print_star_pattern(n: int):
      """Print a pattern of stars that increases in length up to n rows,
      and then decreases back down to 1 row.
      >>> print_star_pattern(3)
      *
      **
      ***
      **
      *
      >>> print_star_pattern(5)
      *
      **
      ***
      ****
      *****
      ****
      ***
      **
      *
      """
  
output:     for i in range(1, n + 1):
          print('*' * i)
      for i in range(n - 1, 0, -1):
          print('*' * i)