How to access object attributes given a string

[Gabriel Genellina]

En Tue, 12 Feb 2008 18:53:36 -0200, Santiago Romero <sromero at gmail.com>  
escribió:
>> Dennis Kempin wrote:
>> You are using a scripting language.. why not use python directly?
>
> I just want to execute an small set of commands (PLAYSOUND, PLAYMUSIC,
> WALKTO, PLAYERSAY, SLEEP and a couple more) ... do you think I can
> write python code inside my object.exec (list attribute) loaded from a
> file?
>  Do you mean that I can replace my "language" by just python (defining
> SETMAP, SLEEP and all those functions somewhere in my main source
> code).

Something like that.
Build a dictionary -that will be used as the script global namespace-  
containing all the required functions, plus a '__builtins__' entry  
(another dict) containing the builtins that you want to provide. For  
example, if you don't want to enable "import", don't include __import__.

import __builtin__
builtins = dict(__builtin__.__dict__) # a copy of the standard __builtin__  
module namespace
del builtins['__import__']

ns = {
   'SETMAP': SETMAP,
   'SHOWTEXT': SHOWTEXT,
   ...
   '__builtins__': builtins
}
exec text_of_the_user_script in ns

Warning: this is unsafe!!!. Malicious users could execute arbitrary code;  
although this may not be an issue if the game runs on the user's own  
system.
The advantage is that you let them use all the power of Python as a  
scripting language.

-- 
Gabriel Genellina