Method safe

tools/python-3.11.9-amd64/Tools/demo/queens.py:38–39

(self, x, y)

                self.remove(x, y)

    def safe(self, x, y):
        return not self.row[y] and not self.up[x-y] and not self.down[x+y]

    def place(self, x, y):
        self.y[x] = y