parent():
    (namesex):
        .name = name
        .sex = sex
    ():
        (.name)

    ():
        .sex == :
            .name:
            .nemechild1(parent):
    ():
        .namechild2(parent):
    ():
        .namec1 = child1(==)
result = c1.football()
(result)
result = c1.talk()
(result)



c2 = child2(==)
result = c2.pingpong()
(result)
(c2.talk())

雪姐 is playing football

雪姐is taiking

None

eden is playing pingpong

edenis taiking

None

问题一：为啥子类实例化后调用了，自己的函数和父类中talk函数，单打印以后会有None

问题二：c1实例化后调用父类中的sex（）函数报错