input: Write a function to generate a checkered pattern of '#' and spaces in a 7x7 grid. The function should print the pattern to the console. If the sum of the row and column indices is even, print '#', otherwise print a space. The function does not take any input and does not return any value.
  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()