Building a function call? (update)

[Duncan Booth]

Francois De Serres wrote:

> Sorry, I was unclear about the fact that the args are formals. I'm 
> trying to do something like:
> 
> func = "dothat"
> args = ('x','y')
> localcontext = ()
> r = None
> while r is None:
>     try:
>         r = eval("dothat(x,y)", None, localcontext) #how do I construct 
> "dothat(x,y)"? with 'dothat(%s,%s)' % args?
>     except NameError:
>         ensure_context(args) #find/compute the formals, eg: localcontext 
>= (('x', 100), ('y', 200))

I think when your code ends up in as big a mess as this, you need to take a 
step back. Forget about asking us how you get at functions or arguments as 
strings, instead tell us what problem you are really trying to solve.

I'm pretty sure that whatever your problem is, the solution won't involve 
using 'eval', and it almost certainly won't involve looking up variables 
or functions from their names.