>>> from dancing_rook import dancing_rook

--ini

>>> l = [1, -2, 2, -1]
>>> dl = dancing_rook(l, 0)
>>> dl == [0, 1, -1, -2] and l == ['.', '.', '.', '.']  
True

>>> l = [1, -2, 2, -1]
>>> dl = dancing_rook(l, 2)
>>> dl == [2] and l == [1, -2, '.', -1]
True

--fi