def board(pos1, pos2):

validate_position(pos1, pos2)

x1, y1 = pos1

x2, y2 = pos2

b = [['_'] * 8 for i in range(8)]

b[x1][y1] = 'W'

b[x2][y2] = 'B'

return [''.join(r) for r in b]

def can_attack(pos1, pos2):

validate_position(pos1, pos2)

x1, y1 = pos1

x2, y2 = pos2

dx = x1 - x2 if x1 >= x2 else x2 - x1

dy = y1 - y2 if y1 >= y2 else y2 - y1

if dx == dy or dx == 0 or dy == 0:

return True

return False

def validate_position(pos1, pos2):

if any(x < 0 or x > 7 for x in pos1 + pos2):

raise ValueError('Invalid queen position: queen out of the board')

if pos1 == pos2:

raise ValueError('Invalid queen position: both queens in the same '

'square: {0}'.format(pos1))