代码片段一

class F(object):
    _b = ['d','a','b','c']
    def __init__(self, **kwargs):
        for i in kwargs.iteritems():
            if i[0] in self._b:
                self.__dict__[i[0]] = i[1]
            else:
                raise AttributeError("error")

f = F(c=33, a=1,b=2, d=445)
print f.a
print f.b
print f.d
print f.c
print dir(f)