Checkers

#!/usr/bin/python3

class Game:
    def __init__(self, width=3, height=3, file="", p1="X", p2="O", win=3):
        self.p1 = p1
        self.p2 = p2
        self.win = win
        self.fill = '_'
        self.sep = ','

        if file != "":
            self.load(file)
        else:
            self.counter = 0
            self.matrix = [[self.fill for _ in range(width)] for _ in range(height)]

    def save(self, file):
        with open(file, 'w') as f:
            f.write("{}\n".format(self.counter))
            f.write("\n".join([self.sep.join(row) for row in self.matrix]))

    def load(self, file):
        self.matrix = []
        with open(file, 'r') as f:
            content = f.read().splitlines()
            self.counter = int(content[0])
            for i in range(1, len(content)):
                self.matrix.append(list(content[i].replace(self.sep, '')))

    def place(self, x, y, char):
        try:
            ret = self.matrix[x][y] == self.fill
            if ret:
                self.matrix[y][y] = char
        except IndexError:
            return False
        return ret

    def check(self, char):
        if char != "":
            for i in range(len(self.matrix)):
                row = self.matrix[i]
                if self._consecutive(row, char):
                    return True

                col = [row[i] for row in self.matrix]
                if self._consecutive(col, char):
                    return True

            dia = [row[i] for i, row in enumerate(self.matrix)]
            if self._consecutive(dia, char):
                return True
        return False

    def _consecutive(self, arr, char):
        if len(arr) >= self.win:
            occ = 0
            for c in arr:
                if c == char:
                    occ += 1
                else:
                    occ = 0
                if occ >= self.win:
                    return True
        return False

    def __str__(self):
        ret = " {}".format(self.fill) * len(self.matrix) + "\n"
        for row in self.matrix:
            ret += "|{}|\n".format("|".join(row))
        return ret

def _main():
    answer = input("Load board from file? (y/N) ").lower()

    if answer == "y":
        answer = input("Enter file name: ")
        game = Game(file=answer)
    else:
        (x, y) = [int(input("Enter width: ")), int(input("Enter height: "))]
        game = Game(width=x, height=y)

    char = ""
    while game.check(char) == False:
        char = game.p2 if game.counter % 2 else game.p1

        print(game)
        print("Player {}'s turn".format(char))
        answer = input("Enter input: ")

        if answer == "q":
            char = ""
            break
        elif answer == "s":
            game.save(input("Enter file name: "))
            print("Game saved!")
        else:
            try:
                (x, y) = map(lambda x: int(x), answer.split(','))
            except ValueError:
                print("Bad input, try again")

            if game.place(x, y, char) == False:
                print("Unavailable position")
            else:
                game.counter += 1

    print(game)
    print("Good bye!" if char == "" else "{} won the game!".format(char))

if __name__ == "__main__":
    _main()