On Fri, 11 Oct 2013 15:36:29 +1100, Cameron Simpson wrote:
> But is it reliable? Will it work on any decorated function?
*Any* decorated function? No, of course not, since decorators can do
anything they like:
def decorate(func):
return lambda *args: "Surprise!"
@decorate
def something_useful(x, y):
return x+y
They don't even have to return a function. Or the function being
decorated can end up in a different cell:
def factory(x, y):
def decorator(func):
def inner(*args):
_ = (x, y) # pretend x and y are useful
return func(*args)
return inner
return decorator
@factory(lambda: None, 42)
def func(a):
return a
py> func.func_closure[0].cell_contents
42
py> func.func_closure[1].cell_contents
<function <lambda> at 0xb7c4609c>
py> func.func_closure[2].cell_contents
<function func at 0xb7c4617c>
So consider this a *cooperative* undecorator. It can only undecorate
things that are decorated the way you expect them to be decorated.
--
Steven
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