这个代码...
class Person:
num_of_people = 0
def __init__(self, name):
self.name = name
Person.num_of_people += 1
def __del__(self):
Person.num_of_people -= 1
def __str__(self):
return 'Hello, my name is ' + self.name
cb = Person('Corey')
kb = Person('Katie')
v = Person('Val')
产生以下错误...
Exception AttributeError: "'NoneType' object has no attribute 'num_of_people'" in <bound method Person.__del__ of <__main__.Person object at 0x7f5593632590>> ignored
但这个代码没有.
class Person:
num_of_people = 0
def __init__(self, name):
self.name = name
Person.num_of_people += 1
def __del__(self):
Person.num_of_people -= 1
def __str__(self):
return 'Hello, my name is ' + self.name
cb = Person('Corey')
kb = Person('Katie')
vb = Person('Val')
我看到的唯一区别是最后一个变量名是"vb"和"v".
我正在学习Python,现在正在研究OOP.