eval vs. exec

[holger krekel]

Simon Budig wrote:
> I want to execute things like the three following strings:
> 
> "a = 2"           ---> returns nothing
> "3 * 4"           ---> returns 12
> "a=2; b=3; a*b"   ---> returns 6
> My current code looks like this:

what you can do is e.g.

def run_code(string, mathstuff={'myabs': lambda x: abs(x)}):
   import code
   interpreter = code.InteractiveInterpreter()
   interpreter.locals = mathstuff
   codeobj = interpreter.compile(string)
   result = interpreter.runcode(codeobj)
   return result

run_code('a=2')
run_code('3*4')
run_code('a=2;b=3;a*b')
run_code('a=-3;myabs(a*5)')

(you should be able to paste it to your interpreter).

Is this what you want? You may need to fiddle around,
of course.

have fun,

    holger