input: def print_pattern(size: int) -> None:
      """ Print a grid pattern with '#' characters for even sums of i and j, 
      and spaces for odd sums.
      >>> print_pattern(7)
      # # # # #
       # # # # #
      # # # # #
       # # # # #
      # # # # #
       # # # # #
      # # # # #
      """
      for i in range(size):
          for j in range(size):
              if (i + j) % 2 == 0:
                  print('#', end='')
              else:
                  print(' ', end='')
          print()
output:     for i in range(size):
          for j in range(size):
              if (i + j) % 2 == 0:
                  print('#', end='')
              else:
                  print(' ', end='')
          print()