Re: [pygame] Python bots in Galcon (or your game!) safe_eval

[Greg Ewing <greg.ewing@xxxxxxxxxxxxxxxx>]

Phil Hassey wrote:

> I spent some time today working on building a safe_eval function that 
> would make it "safe" to run user submitted bots in games

After fixing it to work with Python 2.3, I had a bash
on it, and I couldn't find a way of breaking it in an
evening or so of devious thought. So it looks pretty
good to me so far.

I did notice a couple of restrictions that don't
seem to be necessary:

  * You seem to be disallowing any string literals
    containing "__". This is futile, since you can
    build up any string you want at run time.

  * You're disallowing lambda while allowing def,
    but anything you could do with a lambda could be
    done with a def just as well, as far as I can
    see.

BTW, shouldn't it really be called safe_exec rather
than safe_eval? It works on more than just expressions!

--
Greg