用这种方法遍历dict为什么不行？

Question

class Person(object):
    def __init__(self,name,gender,birth,**kw):
        self.name=name
        self.gender=gender
        self.birth=birth
        for key in kw:
            self.key=kw[key]

xiaoming = Person('Xiao Ming', 'Male', '1990-1-1', job='Student')

print xiaoming.name
print xiaoming.job