Why self?

[Fernando Pérez]

- c o v e n t r y - wrote:

> No, you are only using a convention to let other developers know
> that these variables are private - the python interpreter does not
> even attempt to hide a '__' variable from other classes or code.
> Private members are by convention only in python, they are not
> enforced, thus you do not realistically get a similar result.
> 

wrong. The interpreter mangles the __names automagically by adding the class 
name. You can work around it, but at least it helps to prevent accidents. So 
it is true that it is only a convention, but the interpreter does go to 
reasonable lengths to enforce it:

In [14]: class foo:
   ....:   def __init__(self):
   ....:     self.__priv = 1
   ....:

In [15]: x=foo()

In [16]: x.__priv
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)

?

AttributeError: foo instance has no attribute '__priv'

In [17]: x._foo__priv
Out[17]: 1


cheers,

f.