1 class aa():
 2     
 3     def __init__(self):
 4         self.cc = 6
 5     def do(self):
 6         self.bb=5#无效，只相当于局部变量
 7     def do1(self):
 8         print (self.bb)
 9 aaa=aa()
10 print (dir(aa))#无cc属性
11 print (dir(aaa))#有cc属性
12 #print (aaa.bb)#报错，
13 #aaa.do1()#报错