CODEWITHSUNDEEP
pythonfunctionnesteddecorator
olamundo
olamundo

Reputation: 24981

Is there a way to get the function a decorator has wrapped?

Suppose I have 

@someDecorator
def func():
   '''this function does something'''
   print 1

Now, the object func is an instance of someDecorator. Is there some way I can access the function it holds, i.e something like func.getInnerFunction().

For instance, if I need to retrieve the doc string of func().

Upvotes: 4

Views: 861

Answers (5)

Oin
Oin

Reputation: 7529

You can try using the undecorated library:

With your example func, you could simply do this to return the original function:

undecorated(func)

Upvotes: 0

Peter Hoffmann
Peter Hoffmann

Reputation: 58654

You can attach the wrapped function to the inner function

In [1]: def wrapper(f):
   ...:     def inner():
   ...:         print "inner"
   ...:     inner._orig = f
   ...:     return inner
   ...: 

In [2]: @wrapper
   ...: def foo():
   ...:     print "foo"
   ...:     
   ...:     

In [3]: foo()
inner

In [4]: foo._orig()
foo

Upvotes: 0

Andy Ross
Andy Ross

Reputation: 12043

SilentGhost and sri have partial answers for how to deal with this. But the general answer is no: there is no way to get the "wrapped" function out of a decorated function because there is no requirement that the decorator wrap the function in the first place. It may very well have returned an entirely unrelated function, and any references to your original may have already been garbage collected.

Upvotes: 2

sc45
sc45

Reputation: 1956

See functools.wraps: http://docs.python.org/library/functools.html. The decorator gets the name and doc string of the original function. You use it like this:

def decorator(f):
    @functools.wraps(f)
    def wrapper():
        ....

Upvotes: 4

SilentGhost
SilentGhost

Reputation: 319571

Are you looking for something along these lines?

>>> def dec(f):
    def inner():
        print(f.__doc__)
    return inner

>>> @dec
def test():
    """abc"""
    print(1)


>>> test()
abc

You're passing function explicitly to the decorator, of course you can access it.

Upvotes: 1

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