Counter 类,用于实时检测对象有多少个属性。
class Counter:
def __init__(self):
super().__setattr__('counter', 0)
def __setattr__(self, name, value):
super().__setattr__('counter', self.counter + 1)
super().__setattr__(name, value)
def __delattr__(self, name):
super().__setattr__('counter', self.counter - 1)
super().__delattr__(name)
输出
>>> c = Counter()
>>> c.x = 1
>>> c.counter
1
>>> c.y = 1
>>> c.z = 1
>>> c.counter
3
>>> del c.x
>>> c.counter
2
这串代码中,为什么__setatter__参数中的name参数是“counter”而不是“self.counter”啊?
在实例化之后的c.counter不应该指代的是类中定义的self.counter嘛?