python - 创建 python 工厂方法

Question

我有以下简单示例:

class CatZoo(object):
    def __init__(self):
        raise NotImplemented

    @classmethod
    def make_zoo_cat(cls, name, age, gender, location):
        cls._names = name
        cls._ages = age 
        cls._genders = gender
        cls._location = location
        return cls 

    @classmethod
    def make_zoo_cats(cls, names, ages, genders, location):
        cls._names = names
        cls._ages = ages
        cls._genders = genders
        cls._location = location
        return cls 

    @property
    def location(self):
        return self._location

    @property
    def names(self):
        return self._names

    def age(self, name):
        if name in self._names:
            return self._ages[self._names.index(name)]
        else:
            return None

    def gender(self, name):
        if name in self._names:
            return self._genders[self._names.index(name)]
        else:
            return None

    @property
    def meow(self):
        return "meow!"

我正在尝试使用以下方法创建此类的对象:

cat_zoo = CatZoo.make_zoo_cat('squeakers', 12, 'M', 'KC')
print "The name is {}".format(cat_zoo.names)

这只是一个示例，我只是想让我的工厂方法起作用(make_zoo_cat、make_zoo_cats)。第一个将传递姓名、年龄、性别和位置，第二个将传递姓名、年龄、性别和一个位置的列表。如果我运行这段代码，我会得到以下输出:

The name is <property object at 0x7fe313b02838>

谢谢，

Answer 1

删除 NotImplemented 初始化器并实际创建类的实例，而不是改变类本身:

class CatZoo(object):
    def __init__(self, name, age, gender, location):
        self._names = name
        self._ages = age 
        self._genders = gender
        self._location = location

    @classmethod
    def make_zoo_cat(cls, name, ages, genders, location):
        return cls.mak_zoo_cats([name], age, gender, location)

    @classmethod
    def make_zoo_cats(cls, names, ages, genders, location):
        return CatZoo(names, age, gender, location)

    @property
    def location(self):
        return self._location

    @property
    def names(self):
        return self._names

    def age(self, name):
        if name in self._names:
            return self._ages[self._names.index(name)]
        else:
            return None

    def gender(self, name):
        if name in self._names:
            return self._genders[self._names.index(name)]
        else:
            return None

    @property
    def meow(self):
        return "meow!"

请注意，除了 make_zoo_cat 和 make_zoo_cats 之间的方法名称外，没有真正的区别，参数名称的差异没有改变这里的功能。

相反，我假定 ._names 应该始终是一个列表，并且 make_zoo_cat(单数)应该创建一个具有一个猫名的 CatZoo

请记住 Python is not Java ;你真的不需要所有那些 property 对象，而不是你可以直接访问属性的地方。