Why does python not have a mechanism for data hiding?

[Fuzzyman]

On May 24, 2:58 pm, Ben Finney <bignose+hates-s... at benfinney.id.au>
wrote:
> Sh4wn <luckyluk... at gmail.com> writes:
> > first, python is one of my fav languages, and i'll definitely keep
> > developing with it. But, there's 1 one thing what I -really- miss:
> > data hiding. I know member vars are private when you prefix them with
> > 2 underscores, but I hate prefixing my vars, I'd rather add a keyword
> > before it.
>
> From whom are you trying to hide your attributes?

Actually, 'data hiding', although vastly overused by the static crowd
can be a reasonable thing to want.

For example, at Resolver Systems we expose the spreadsheet object
model to our users. It hasa public, documented, API - plus a host of
undocumented internally used methods.

We would really *much* rather hide these, because anything our
customers start using (whether documented or not) we will probably
have to continue supporting and maintaining.

The 'we told you not to use that' approach, when applied to paying
customers doesn't really work... all they see is that you broke their
spreadsheet code by changing your API.

You can make members truly private by proxying, but it is a bit
ungainly.

Michael Foord
http://www.ironpythoninaction.com/


>
> In Python, the philosophy "we're all consenting adults here" applies.
> You shouldn't pretend to know, at the time you write it, all the uses
> to which your code will be put. Barriers such as enforced "private"
> attributes will only cause resentment when people, despite your
> anticipations, *need* to access them and are then forced to hack their
> way around them.
>
> If you want the users of your code to know that an attribute should
> not be used as a public API for the code, use the convention of naming
> the attribute with a single leading underscore. This is a string
> signal that the attribute is part of the implementation, not the
> interface. The reader is then on notice that they should not rely on
> that attribute; but they are not *prohibited* from using it if
> necessary to their ends.
>
> > Python advertises himself as a full OOP language, but why does it
> > miss one of the basic principles of OOP?
>
> Who taught you that enforced restrictions on attribute access was a
> "basic principle" of OO?
>
> Perhaps you're confusing the "encapsulation" and "abstraction"
> principles for enforced access restrictions; they're not.
>
> > Will it ever be added to python?
>
> I hope not.
>
> --
>  \            "Why was I with her? She reminds me of you. In fact, she |
>   `\             reminds me more of you than you do!"  -- Groucho Marx |
> _o__)                                                                  |
> Ben Finney