Python对多个构造函数使用classmethod

Question

我一直在努力用classmethoddecorator创建多个构造函数。SO-What is a clean, pythonic way to have multiple constructors in Python?（第二个答案）中有一个例子

class Cheese(object):
    def __init__(self, num_holes=0):
        "defaults to a solid cheese"
        self.number_of_holes = num_holes

    @classmethod
    def random(cls):
        return cls(random(100))

    @classmethod
    def slightly_holey(cls):
    return cls(random(33))

    @classmethod
    def very_holey(cls):
        return cls(random(66, 100))

但是，这个示例不是很清楚，在python 3中键入给定的命令时，代码对我不起作用：

gouda = Cheese()
emmentaler = Cheese.random()
leerdammer = Cheese.slightly_holey()

给予-

AttributeError: type object 'Cheese' has no attribute 'random'

因为这是我能找到的唯一的例子之一。你知道吗

Answer 1

randint应该有效：

from random import randint

class Cheese(object):
    def __init__(self, num_holes=0):
        "defaults to a solid cheese"
        self.number_of_holes = num_holes

    @classmethod
    def random(cls):
        return cls(randint(0, 100))

    @classmethod
    def slightly_holey(cls):
        return cls(randint(0, 33))

    @classmethod
    def very_holey(cls):
        return cls(randint(66, 100))

gouda = Cheese()
emmentaler = Cheese.random()
leerdammer = Cheese.slightly_holey()

现在：

>>> leerdammer.number_of_holes
11
>>> gouda.number_of_holes
0
>>> emmentaler.number_of_holes
95