input: def print_star_pattern() -> str:
      """Prints a specific pattern of asterisks.
      The pattern starts with a single asterisk on the first line,
      increases by one asterisk per line until it reaches five lines,
      then decreases by one asterisk per line until it reaches the first line again.
      >>> print_star_pattern()
      *
      **
      ***
      ****
      *****
      ****
      ***
      **
      *
      """
      for i in range(5):
          for j in range(i+1):
              print("*", end="")
          print("")
      for i in range(5, 0, -1):
          for j in range(i):
              print("*", end="")
          print("")
output:     for i in range(4, 0, -1):
          for j in range(i):
              print("*", end="")
          print("")