Get decorated function from within nested decorator

Question

I'm trying to get the reference to the originally decorated function from within a decorator. How can this be done?

import inspect
from functools import wraps


def test_decorator(func):
    @wraps(func)
    def wrapper(*args, **kwargs):
        # the closest I could get to getting the original function:
        # it prints the frame from which the function was called.
        current_frame = inspect.currentframe()
        outer_frames = inspect.getouterframes(current_frame)
        print(outer_frames[-1].frame)
        
        return func(*args, **kwargs)
    return wrapper


@test_decorator
@test_decorator
@test_decorator
def test_func(a, b, c):
    print("func")


test_func(1,2,3)

The 'originally decorated function' in this context would be test_func, since it's the target function we're decorating. I've looked through the inspect module, the closest I could get is by getting the first frame on the stack, but it doesn't help much.

Maybe, there is a solution already in stdlib?

Answer 1

This:

https://github.com/micheles/decorator

import inspect
from decorator import decorator


@decorator
def test_decorator(func, *args, **kwargs):
    print(inspect.getfullargspec(func))
    return func(*args, **kwargs)


@test_decorator
@test_decorator
@test_decorator
def test_func(a, b, c):
    print("func")


test_func(1,2,3)

Now from within each test_decorator it prints:

FullArgSpec(args=['a', 'b', 'c'], varargs=None, varkw=None, defaults=None, kwonlyargs=[], kwonlydefaults=None, annotations={})

Bless this man who wrote the module, the guy is a legend.