Python – How do I instantiate a function from a string in Python 3.x?

I have a string with the full text of a function :

my_str = 'def my_fn(a, b):\n    return a+b'

I want my program to be able to instantiate my_func, save it to an object, and call it later.

exec(my_str) returns <function my_fn at ... > viewed on the command line, it is undefined at runtime. eval(my_str) returns SyntaxError: invalid syntax is not really what I want anyway.

I’m confused here. How do I get my function variable from this string?

It would be a nice bonus if I could later rename the function to something else (didn’t know its name at first).

Note: I know it’s dangerous to use exec. If there is a better way to do this, I am open to suggestions. For now, this is just a research code. It runs locally, I show people how to use it, it doesn’t run on the internet.

I think you want to do it
exec(my_str, globals())
It will be put into a global dictionary, allowing you to access it