封装之如何隐藏属性

class A:
    __x = 1     #   _A__x = 1

    def __init__(self,name):

        self.__name=name       # self._A__name = name

    def __foo(self):            # _A__foo
        print('run foo')

# print(A.__dict__)
'''{'__module__': '__main__', '_A__x': 1, '__init__': <function A.__init__ at 0x0000017B28A1F950>, '_A__foo': 
<function A.__foo at 0x0000017B28A1F488>, '__dict__': <attribute '__dict__' of 'A' objects>, '__weakref__': 
<attribute '__weakref__' of 'A' objects>, '__doc__': None}
'''
'''
这种变形的特点：
    1、外部无法直接使用：obj.__AttrName
    2、在类内部是可以直接使用：obj.__AttrName
    3、子类无法覆盖父类__开头的属性

'''

class A:
    def foo(self):
        print('A foo')

    def bar(self):
        print('A bar')
        self.foo()

class B(A):
    def foo(self):
        print('b foo')

b1 = B()
b1.bar()
# 结果
# A bar
# b foo

class A:
    def __foo(self):
        print('A foo')

    def bar(self):
        print('A bar')
        self.__foo()

class B(A):
    def __foo(self):
        print('b foo')

b1 = B()
b1.bar()
# 结果
# A bar
# A foo