需要一个类来跟踪创建了多少不同类型的类

Question

我有一个动物类定义为：

class Animal:
    counter = 0
     
    def __init__(self, species, sound):
        self.species=species
        self.sound=sound
        Animal.counter += 1
        
    def make_sound(self):
        return self.sound
    
    def number_of_your_species(self):
        return self.counter 

我想要number\u of_your\u species方法返回创建了多少种不同类型的物种。上面的代码不起作用，因为它返回类动物已实例化的总数。 换句话说，我希望下面返回2（猫）和1（狗）：

tom = Animal("cat","miau")
pluto = Animal("dog","guau")
misifu = Animal("cat","miau")

tom.number_of_your_species()
pluto.number_of_your_species()

Answer 1

class Animal:
    counter = dict()
     
    def __init__(self, species, sound):
        self.species=species
        self.sound=sound
        if species not in Animal.counter:
            Animal.counter[species] = 0
        Animal.counter[species] += 1
        
    def make_sound(self):
        return self.sound
    
    def number_of_your_species(self):
        return Animal.counter[self.species]