Why does python not have a mechanism for data hiding?

[Paul Boddie]

On 11 Jun, 21:28, "Russ P." <Russ.Paie... at gmail.com> wrote:
>
> All I did was to suggest that a keyword be added to Python to
> designate private data and methods without cluttering my cherished
> code with those ugly leading underscores all over the place. I don't
> like that clutter any more than I like all those semi-colons in other
> popular languages. I was originally attracted to Python for its clean
> syntax, but when I learned about the leading-underscore convention I
> nearly gagged.

I'm not bothered about having private instance data, but I think
there's definitely a case to be answered about the double-underscore
name-mangling convention. In the remote past, people were fairly
honest about it being something of a hack, albeit one which had mostly
satisfactory results, and unlike the private instance data argument
which can often be countered by emphasising social measures, there has
been genuine surprise about this particular method of preventing
attribute name collisions - it's an issue which can trip up even
careful programmers.

Note also that the double-underscore convention is listed as a Python
wart [1] and is described by Kuchling thus:

"But it's a hack and a kludge; making privacy depend on an unrelated
property such as the attribute's name is clumsy. At least this
ugliness is limited to one specific and little-used case; few Python
programmers ever bother to use this private variable feature."

In my opinion there are too many people either defending the status
quo (warts and all) or pushing the envelope in many areas that didn't
overly bother people before (various Python 3000 features).

Paul

[1] http://wiki.python.org/moin/PythonWarts