关于__dict__

class A(object):
    class_var = 1
    def __init__(self):
        self.name = 'xy'
        self.age = 2

    #@property
    def num(self):
        return self.age + 10

    def fun(self):pass
    def static_f():pass
    def class_f(cls):pass

if __name__ == '__main__':#主程序
    a = A()
    print (a.__dict__)   #{'age': 2, 'name': 'xy'}   实例中的__dict__属性
    print (A.__dict__)

    a.addr='ssdd'        #新增一个元素addr
    print(a.__dict__)

    a.num=10
    print(a.num)
    print(a.__dict__)

运行结果：

{'name': 'xy', 'age': 2}
{'__doc__': None, '__module__': '__main__', 'static_f': <function A.static_f at 0x00000264AC4D0620>, 'class_f': <function A.class_f at 0x00000264AC4D06A8>, 'class_var': 1, 'num': <function A.num at 0x00000264AC4D0510>, '__init__': <function A.__init__ at 0x00000264AC4D0158>, 'fun': <function A.fun at 0x00000264AC4D0598>, '__dict__': <attribute '__dict__' of 'A' objects>, '__weakref__': <attribute '__weakref__' of 'A' objects>}
{'name': 'xy', 'age': 2, 'addr': 'ssdd'}
10
{'age': 2, 'num': 10, 'name': 'xy', 'addr': 'ssdd'}