On Tue, May 31, 2011 at 6:04 PM, Daniel Kluev <dan.kl...@gmail.com> wrote: > On Wed, Jun 1, 2011 at 3:16 AM, Ian Kelly <ian.g.ke...@gmail.com> wrote: >> >> There is no "decorator" module in the standard library. This must be >> some third-party module. The usual way to do this would be: > > Yes, but its very useful for decorators and provides some > not-readily-available functionality. > http://pypi.python.org/pypi/decorator/3.3.1 > >> Note that this will always work, whereas the "decorator.decorator" >> version will break if the decorated function happens to take a keyword >> argument named "f". > > No, it will not. Its the magic of decorator library, it is > signature-preserving, while your variant breaks function signature and > causes problems to any code that relies on signatures (happens with > Pylons, for example).
Ah, I see. I assumed it was much simpler than it is. I found a way to break it with Python 3, though: >>> @copy_args ... def test(*, f): ... return f ... >>> test(f=1) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<string>", line 2, in test File "<stdin>", line 6, in copy_args TypeError: test() needs keyword-only argument f The interesting thing here is that the decorated function has exactly the correct function signature; it just doesn't work. Cheers, Ian -- http://mail.python.org/mailman/listinfo/python-list