實例化過程:
class luffy_stu:
def __init__(self,name,age,sex):
self.name = name
self.age = age
self.sex = sex
def eat(self):
pass
if __name__=="__main__":
stu1 = luffy_stu('bao',21,'male')
#實例化過程:
#1. 是先產生一個stu1對象,
#2. luffy_stu.__init__('stu1','bao',21,'male')再將stu1對象傳入__init__構造函數中實例化對象.


