在内的内部定义并使用，外部无法访问，以双下划线作为前作，定义后被python转为
_classname__变量名了
--------------------------------------------------------------------------------------
In [1]: class aa:
...: __x = 12 #私有变量_ _x
...: def px(self):
...: print ‘private __x‘, aa.__x #内部访问
...:
In [2]: a = aa()
In [3]: a.px()
private __x 12
In [4]: dir(a)
Out[4]: [‘__doc__‘, ‘__module__‘, ‘_aa__x‘, ‘px‘] # map成_classname__变量名了
In [5]: a.__x = 13#实例对象a的实例变量
In [6]: dir(a)
Out[6]: [‘__doc__‘, ‘__module__‘, ‘__x‘, ‘_aa__x‘, ‘px‘]
In [7]: print a.__x
13
In [8]:In [8]: print aa.__x
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
<ipython-input-8-34f87438b5b5> in <module>()
----> 1 print aa.__x
AttributeError: class aa has no attribute ‘__x‘
In [9]:
-----------------------------------------------------------python的私有变量解析,布布扣,bubuko.com
python的私有变量解析
原文：http://blog.csdn.net/jeapeducom/article/details/24884081
