幾段 Python 代碼理解面向對象

2018-07-20 來源：編程學習網

正文

1.定義一個游戲輸入，對輸入簡單解析并做出反應

源代碼：

a-simple-game.py

# 獲取輸入并解析出輸入對應的動作
def get_input():
    command = input(":").split()
    verbo_word = command[0]
    if verbo_word in verb_dict:
        verb = verb_dict[verbo_word]
    else:
        print("Unknown verb {}".format(verbo_word))
        return

    if len(command) >= 2:
        noun_word = command[1]
        print(verb(noun_word))
    else:
        print(verb("nothing"))

# 具體的動作
def say(noun):
    return "You said {}".format(noun)

# 將動詞和動作對應起來
verb_dict = {
    "say": say,
}

while True:
    get_input()

運行結果：

2.為游戲對象添加查看狀態(tài)的方法

代碼：

class GameObject:
    class_name = ""
    desc = ""
    objects = {}

    def __init__(self, name):
        self.name = name
        GameObject.objects[self.class_name] = self

    def get_desc(self):
        return self.class_name + "\n" + self.desc


# 創(chuàng)建一個繼承自游戲對象類的哥布林類
class Goblin(GameObject):
    class_name = "goblin"
    desc = "A foul creature"

goblin = Goblin("Gobbly")

# 具體的動作
def examine(noun):
    if noun in GameObject.objects:
        return GameObject.objects[noun].get_desc()
    else:
        return "There is no {} here.".format(noun)

以上代碼創(chuàng)建了一個繼承自 GameObject 類的 Goblin 類，也創(chuàng)建一個新的 examine 方法，于是我們添加一個新的 examine 動詞進去：

# 將動詞和動作對應起來
verb_dict = {
    "say": say,
    "examine": examine,
}

代碼和上一個小 demo 合并起來，運行看看：

3.為 Goblin 類添加更詳細的信息，并添加 hit 動作，讓你可以打 Goblin（有點意思了~）

代碼（只列出修改過的與添加的）：

class Goblin(GameObject):
    def __init__(self, name):
        self.class_name = "goblin"
        self.health = 3
        self._desc = "A foul creature"
        super().__init__(name)

    @property
    def desc(self):
        if self.health >= 3:
            return self._desc
        elif self.health == 2:
            health_line = "It has a wound on its knee."
        elif self.health == 1:
            health_line = "Its left arm has been cut off."
        elif self.health <= 0:
            health_line = "It is dead."
        return self._desc + "\n" + health_line

    @desc.setter
    def desc(self, value):
        self._desc = value

def hit(noun):
    if noun in GameObject.objects:
        thing = GameObject.objects[noun]
        if type(thing) == Goblin:
            thing.health -= 1
            if thing.health <= 0:
                msg = "You killed the goblin!"
            else:
                msg = "You hit the {}".format(thing.class_name)
        else:
            msg = "I'm not strong enough, I can only hit goblin."
    else:
        msg = "There is no {} here.".format(noun)
    return msg

# 將動詞和動作對應起來
verb_dict = {
    "say": say,
    "examine": examine,
    "hit": hit,
}

運行：