Simple Python Sandbox

[Steven D'Aprano]

On Sun, 15 Aug 2010 01:24:00 +0200, Roland Koebler wrote:

> I had the same problem, and so I created a "pseudo-sandbox" for
> embedding Python in templates. This "pseudo-sandbox" creates a
> restricted Python environment, where only whitelisted functions/classes
> are allowed. Additionally, it prevents things like '0 .__class__'.

Hmmm... is that meant just as an illustration of a general technique, or 
do you actually have something against the class of 0? 0 .__class__ seems 
pretty innocuous to me:

>>> type(0) is 0 .__class__ is int
True


[...]
> But note that this is not a real sandbox! As soon as you allow *any*
> unsafe function (e.g. open, import, eval, getattr etc.), you can easily
> break out.

Isn't that true of any sandbox though? Surely by definition, if you allow 
an unsafe function in any sandbox, it's no longer an effective sandbox.


-- 
Steven