How do I get the return value when using Python exec on the code object of a function?

Question

For testing purposes I want to directly execute a function defined inside of another function.

I can get to the code object of the child function, through the code (

Answer 1

While this is the ugliest beast ever seen by mankind, this is how you can do it by using a global variable inside your exec call:

def my_exec(code):
    exec('global i; i = %s' % code)
    global i
    return i

This is misusing global variables to get your data across the border.

>>> my_exec('1 + 2')
3

Needless to say that you should never allow any user inputs for the input of this function in there, as it poses an extreme security risk.