input: Write a function to generate a checkboard pattern within a 7x7 grid. The function should print out the grid where '#' represents a cell in the checkboard and ' ' represents an empty cell. If the sum of the row and column indices is even, a '#' should be printed; otherwise, a space should be printed. The function should not return any value but should print the pattern directly.
  
  
  def generate_checkerboard():
      for i in range(7):
          for j in range(7):
              if (i + j) % 2 == 0:
                  print('#', end='')
              else:
                  print(' ', end='')
          print()
  
  assert generate_checkerboard() # This assert is just to ensure the function is called and does not return any value
  
output: def generate_checkerboard():
      for i in range(7):
          for j in range(7):
              if (i + j) % 2 == 0:
                  print('#', end='')
              else:
                  print(' ', end='')
          print()