大爽Python入门教程 7-2 面向对象编程使用类`class`组织代码

Z时代
2024-01-10
分类：综合

python

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在之前的，第六章第9小节，实现了一个井字棋小游戏。

其代码是面向过程的，换言之使用函数来组织的。

这里我们把这个游戏，功能不变，换种写法。

使用类来重新组织下代码。

这种写法是不唯一的，有非常多种写法，以下本人只是展示了一种，供大家参考。

1 思路分析

这里用一个类去实现，直接给其起名为Game

这个Game类

应该有以下属性

board: 存储棋盘棋子信息的二维列表

current: 当前玩家棋子符号。

应该有以下方法

generate_board: 生成board

show_board: 展示board

check_bunch_match: 检查某一串是否全部为当前棋子

check_win: 检查当前玩家是否胜利
（当前玩家落子能否连成一条线）

place: 放置棋子

turn: 切换玩家

parse_rc: 解析用户输入命令中的行与列

run: 运行游戏

2 代码框架

初步代码框架如下

WELCOME = "Welcome to Tic-Tac-Toe!"
ENTER  = "%s's turn. Enter row index and column index to place (ri, ci):\n"
Invalid = "Invalid command."
Used = "The place is already occupied."
class Game:
    def __init__(self):
        self.board = []
        self.current = "X"
    def generate_board(self):
        pass
    def show_board(self):
        pass
    def check_bunch_match(self, bunch):
        return False
    def check_win(self):
        return False
    def place(self, ri, ci):
        return True
    def turn(self):
        pass
    def parse_rc(self, cmd):
        return -1, -1
    def run(self):
        while True:
            pass
game = Game()
game.run()

3 总代码

将上面框架中的方法，逐步实现后如下

WELCOME = "Welcome to Tic-Tac-Toe!"
ENTER  = "%s's turn. Enter row index and column index to place (ri, ci):\n"
Invalid = "Invalid command."
Used = "The place is already occupied."
class Game:
    def __init__(self):
        self.generate_board()
        self.current = "X"
    def generate_board(self):
        self.board = [
            [" " for ci in range(3)] for ri in range(3)
        ]
    def show_board(self):
        for ri, row in enumerate(self.board):
            row_str = ""
            for ci, cell in enumerate(row):
                row_str += " %s " % cell
                if ci != 2:
                    row_str += "|"
            print(row_str)
            if ri != 2:
                print("---+---+---")
    def check_bunch_match(self, bunch):
        res = True
        for one in bunch:
            if one != self.current:
                res = False
                break
        return res
    def check_win(self):
        r, c = len(self.board), len(self.board[0])
        for ri in range(r):
            row = self.board[ri]
            if self.check_bunch_match(row):
                return True
        for ci in range(c):
            column = [self.board[ri][ci] for ri in range(r)]
            if self.check_bunch_match(column):
                return True
        diagonal_1 = [self.board[ri][ri] for ri in range(r)]
        diagonal_2 = [self.board[ri][c - ri - 1] for ri in range(r)]
        if self.check_bunch_match(diagonal_1):
            return True
        if self.check_bunch_match(diagonal_2):
            return True
        return False
    def place(self, ri, ci):
        if self.board[ri][ci] != " ":
            return False
        self.board[ri][ci] = self.current
        return True
    def turn(self):
        if self.current == "X":
            self.current = "O"
        else:
            self.current = "X"
    def parse_rc(self, cmd):
        rc = cmd.split(",")
        if len(rc) == 2:
            ri, ci = rc
            ri = ri.strip()
            ci = ci.strip()
            if ci.isdigit() and ri.isdigit():
                ci = int(ci)
                ri = int(ri)
                if 0 <= ci < 3 and 0 <= ri < 3:
                    return ri, ci
        return -1, -1
    def run(self):
        print(WELCOME)
        while True:
            self.show_board()
            cmd = input(ENTER % self.current)
            ri, ci = self.parse_rc(cmd)
            if ri >= 0:
                res = self.place(ri, ci)
                if res:
                    if self.check_win():
                        self.show_board()
                        print("%s win!" % self.current)
                        return
                    self.turn()
                else:
                    print(Used)
            else:
                print(Invalid)
game = Game()
game.run()