input: 
  def generate_chessboard_pattern() -> None:
      """ Generate a 7x7 pattern resembling a chessboard, where '#' represents 
      a black square and ' ' represents a white square. The pattern starts and 
      ends with '#'.
      >>> generate_chessboard_pattern()
      # # # # #
        # # # # # 
      # # # # #
        # # # # # 
      # # # # #
        # # # # # 
      # # # # #
      """
      for i in range(7):
          for j in range(7):
              if (i + j) % 2 == 0:
                  print('#', end='')
              else:
                  print(' ', end='')
          print()
  
output:     for i in range(7):
          for j in range(7):
              if (i + j) % 2 == 0:
                  print('#', end='')
              else:
                  print(' ', end='')
          print()