play connect 4 with python (I think this works)

connect4.py

class Connect4:
    COLOR_BLUE = 1
    COLOR_RED = 2
    EMPTY = -1
    NORTH = 1
    SOUTH = 2
    EAST = 3
    WEST = 4
    NORTH_EAST = 5
    NORTH_WEST = 6
    SOUTH_EAST = 7
    SOUTH_WEST = 8
    directions = [NORTH, SOUTH, EAST, WEST, NORTH_EAST, NORTH_WEST, SOUTH_EAST, SOUTH_WEST]
    last_color = -1
    game_over = False

    board = [
        [-1, -1, -1, -1, -1, -1, -1],
        [-1, -1, -1, -1, -1, -1, -1],
        [-1, -1, -1, -1, -1, -1, -1],
        [-1, -1, -1, -1, -1, -1, -1],
        [-1, -1, -1, -1, -1, -1, -1],
        [-1, -1, -1, -1, -1, -1, -1]
    ]

    def addPiece(self, column, color):

        if self.game_over:
            return -1

        if column >= len(self.board[0]) or color not in [self.COLOR_RED, self.COLOR_BLUE]:
            return -1

        if self.last_color != color:
            self.last_color = color
        else:
            return -1

        x = -1
        while (x < len(self.board) - 1):
            x = x + 1
            if self.board[x][column] != self.EMPTY:
                x = x - 1
                break

        if x >= len(self.board):
            return -1

        if self.board[x][column] != self.EMPTY:
            return -1

        self.board[x][column] = color

        if self.winner(x, column, color) == color:
            self.game_over = True
            return color
        return 0

    def cnt(self, direction, row, column, color):
        if direction == self.NORTH:
            x = 0
            y = -1
        elif direction == self.SOUTH:
            x = 0
            y = 1
        elif direction == self.EAST:
            x = 1
            y = 0
        elif direction == self.WEST:
            x = -1
            y = 0
        elif direction == self.NORTH_WEST:
            x = -1
            y = -1
        elif direction == self.SOUTH_WEST:
            x = -1
            y = 1
        elif direction == self.NORTH_EAST:
            x = 1
            y = -1
        elif direction == self.SOUTH_EAST:
            x = 1
            y = 1
        else:
            return 0

        next_col = column + x
        next_row = row + y
        cumulator = 0
        while len(self.board[0]) > next_col >= 0 and 0 <= next_row < len(self.board):
            if self.board[next_row][next_col] == color:
                cumulator = cumulator + 1
            next_col = next_col + x
            next_row = next_row + y

        return cumulator

    def winner(self, row, column, color):
        n_cnt = self.cnt(self.NORTH, row, column, color)
        s_cnt = self.cnt(self.SOUTH, row, column, color)
        if n_cnt + s_cnt + 1 >= 4:
            return color
        nw_cnt = self.cnt(self.NORTH_WEST, row, column, color)
        se_cnt = self.cnt(self.SOUTH_EAST, row, column, color)
        if nw_cnt + se_cnt + 1 >= 4:
            return color

        e_cnt = self.cnt(self.EAST, row, column, color)
        w_cnt = self.cnt(self.WEST, row, column, color)
        if e_cnt + w_cnt + 1 >= 4:
            return color

        sw_cnt = self.cnt(self.SOUTH_WEST, row, column, color)
        ne_cnt = self.cnt(self.NORTH_EAST, row, column, color)
        if sw_cnt + ne_cnt + 1 >= 4:
            return color

        return -1


game = Connect4()
game.addPiece(0, game.COLOR_RED)
game.addPiece(1, game.COLOR_BLUE)
game.addPiece(0, game.COLOR_RED)
game.addPiece(1, game.COLOR_BLUE)
game.addPiece(0, game.COLOR_RED)
game.addPiece(5, game.COLOR_BLUE)
assert(not game.game_over)
assert (game.addPiece(0, game.COLOR_RED) == game.COLOR_RED)
assert(game.game_over)