使用函数变量调用类实例时，Python 'str‘对象没有'name’属性

Question

我刚刚开始学习使用python编程。我正在尝试制作一个类似于精灵宝可梦的游戏，并且我正在尝试将OOP应用到游戏中。

我首先创建了一个精灵宝可梦类，并添加了类定义的属性，如name、HP、etype、attacks。“攻击”是一个列表字典。

我现在的问题是，我正在尝试开发一个简单的战斗引擎，我可以在其中切换口袋妖怪。出于这个原因，我创建了一个函数/方法名fight()。

在里面我有一个名为current_pokemon.name的变量，所以每当我切换口袋妖怪的时候，我都可以使用新的口袋妖怪的名字，攻击，等等。

我使用raw_input返回一个字符串来替换current_pokemon，它有一个.name属性可以在pikachu实例上调用。相反，我得到的'str‘对象没有属性。为什么这个不起作用？当我显式地编写pikachu.attribute时，它可以在fight()函数之外工作。

class Pokemon(object):
    def __init__(self, name, HP, etype, attacks):
        self.name = name
        self.HP = HP
        self.etype = etype
        self.attacks = attacks #2 attacks with name, dmg, type and power points

geodude = Pokemon("Geodude", 100, "Ground", 
                  attacks = 
                  {"Tackle":["Tackle",30,"Normal","35"], 
                   "Rollout":["Rollout",50,"Rock","20"]
                  })
                    #attacks = {attack:[attack_name, dmg, type, PP]}

pikachu = Pokemon("Pikachu", 100, "Lightning", 
                  attacks = 
                  {"Thunder Shock":["Thunder Shock",40,"Electric"],
                   "Quick Attack":["Quick Attack",40,"Normal"]
                  })

#selects pikachu's attack
print "Pokemon's name is", (pikachu.name)
print "Pikachu's %s attack damages %d" % ((pikachu.attacks["Thunder Shock"][0]),(pikachu.attacks["Thunder Shock"][1]))

pikachu.HP = pikachu.HP - geodude.attacks["Rollout"][1]
print "Pikachu's HP is", (pikachu.HP)
pikachu.HP = pikachu.HP - geodude.attacks["Tackle"][1]
print "Pikachu's HP is", (pikachu.HP)

#Pokemon Battle test with stored variable
#Value selector - replace all var attributes using an easy function
#Use Solution 2

def fight():
    current_pokemon = raw_input("pikachu or geodude? > ")
    print current_pokemon.name
    print current_pokemon.attacks


fight()

输出：

Pokemon's name is Pikachu
Pikachu's Thunder Shock attack damages 40
Pikachu's HP is 50
Pikachu's HP is 20
pikachu or geodude? > pikachu
Traceback (most recent call last):
  File "poke_game_stack.py", line 40, in <module>
    fight()
  File "poke_game_stack.py", line 36, in fight
    print current_pokemon.name
AttributeError: 'str' object has no attribute 'name'

请帮我解决这个简单的问题！谢谢!

Answer 1

raw_input()总是返回一个字符串；它不会返回以相同名称存储的对象。

将pokemons存储在字典中(将字符串映射到对象)，然后使用raw_input()中的字符串映射到其中一个对象：

pokemons = {
    'geodude': Pokemon("Geodude", 100, "Ground", 
                  attacks = 
                  {"Tackle":["Tackle",30,"Normal","35"], 
                   "Rollout":["Rollout",50,"Rock","20"]
                  }),

    'pikachu': Pokemon("Pikachu", 100, "Lightning", 
                  attacks = 
                  {"Thunder Shock":["Thunder Shock",40,"Electric"],
                   "Quick Attack":["Quick Attack",40,"Normal"]
                  }),
}

def fight():
    current_pokemon_name = raw_input("pikachu or geodude? > ")
    current_pokemon = pokemons[current_pokemon_name]
    print current_pokemon.name
    print current_pokemon.attacks

Answer 2

current_pokemon = raw_input("pikachu or geodude? > ")
print current_pokemon.name
print current_pokemon.attacks

raw_input()方法返回一个str，字符串没有name或attacks等属性。

该函数从输入中读取行，将其转换为字符串(去掉尾随的换行符)，并返回该字符串。当读取EOF时，将引发EOFError。