为什么父类已经有name了，子类还要重新传入name呢？
class Person(object):
def __init__(self, name, gender):
self.name = name
self.gender = gender
class Teacher(Person):
def __init__(self, name, gender, course):
super(Teacher,self).__init__(course)
self.course=course
t = Teacher('Alice', 'Female', 'English')
print t.name
print t.course
