实例三，在特殊方法中除self之外定义2个形参

class SomeClass2(object):
    def __init__(self, data1, data2):
       self.data1 = data1
       self.data2 = data2
sc2 = SomeClass2(18, 20)
print(sc2)                      # <__main__.SomeClass2 object at 0x7f127bc0d8d0>