Python类的getitem和setitem特殊方法

class testsetandget:
    kk = {};
    def __getitem__(self, key):
        return self.kk[key];
    def __setitem__(self, key, value):
        self.kk[key] = value;

a = testsetandget()
a['first'] = 1
print a['first']

a.__setitem__('second', 2)
print a.__getitem__('second')
print a['second']