自定义dict

class Test1(dict):
    def __init__(self):
        self.update()
        self.load()

    def update(self):
        print 'update 执行'

    def load(self):
        k = 'key'
        v = 'value'
        dict.__setitem__(self,k,v)
    def __setitem__(self, key, value):
        print '__setitem__ 执行'
        self.__dict__[key] = value
        return dict.__setitem__(self,'k1','v1')

t = Test1()
t['a'] = 'b'
print t.__dict__    # {'a':'b'}
print t.get('key')  # value
print t.get('a')    # Noneprint t.get('k1')   # v1