input: def generate_chessboard(rows: int, cols: int) -> None:
      """ Generates a chessboard pattern with the given number of rows and columns.
      Each cell in the chessboard is either a # or a space character, based on whether
      the sum of the row index and column index is even or odd.
      >>> generate_chessboard(7, 7)
      # # # # # # #
       # # # # # # 
      # # # # # # #
       # # # # # # 
      # # # # # # #
       # # # # # # 
      # # # # # # #
      """
      for i in range(rows):
          for j in range(cols):
              if (i + j) % 2 == 0:
                  print('#', end='')
              else:
                  print(' ', end='')
          print()
output:     for i in range(rows):
          for j in range(cols):
              if (i + j) % 2 == 0:
                  print('#', end='')
              else:
                  print(' ', end='')
          print()