input: from typing import List
  
  def print_star_pattern(rows: int) -> None:
      """Print a star pattern which starts with one star on the first row, 
      increasing by one star per row until it reaches the specified number of rows, 
      then decreases by one star per row back to one star. 
  
      >>> print_star_pattern(3)
      *
      **
      ***
      **
      *
      >>> print_star_pattern(5)
      *
      **
      ***
      ****
      *****
      ****
      ***
      **
      *
      """
output:     for i in range(1, rows + 1):
          print('*' * i)
      for i in range(rows - 1, 0, -1):
          print('*' * i)