input: 
  def print_checkerboard():
      """
      Prints a 7x7 checkerboard pattern with hashes (#) on even positions and spaces on odd positions.
      >>> print_checkerboard()
      # # # # # 
       # # # # #
      # # # # # 
       # # # # #
      # # # # # 
       # # # # #
      # # # # # 
      """
  
output:     for i in range(7):
          if i % 2 == 0:
              print("# # # # #")
          else:
              print(" # # # # #")