Overriding warnings.showwarning() with a c/python module function (from a c/python module) doesn't work because warn_explicit() only allow PyFunction or PyMethod objects to be called (unfortunately c/python module functions are of type PyCFunction).

Suggested changes in _warnings.c (from py3k) - not tested at all:

from:
412            if (!PyMethod_Check(show_fxn) && !PyFunction_Check(show_fxn)) {
413                PyErr_SetString(PyExc_TypeError,
414                                "warnings.showwarning() must be set to a "
415                                "function or method");

to:
412            if (!PyCallable_Check(show_fxn)) {
413                PyErr_SetString(PyExc_TypeError,
414                                "warnings.showwarning() must be set to a "
415                                "callable");

brett,

is there any chance for this to make it in?

Not for 3.2.0, no as it's such a minor "fix". Chance this can go into 3.2.1, though. Definitely for 3.3.

- split the patch between the actual fix and the test
- rewrote the test a little bit (I'm not sure it's even needed, hence the split)
- rediff against 3.3 (should still apply cleanly on top of 3.2 (modulo offset))

Is there anything else I should be doing?

Brett's been very busy with real life.  Maybe someone else can commit this.

how should we go about that?

New changeset aaced3dcb858 by Brett Cannon in branch 'default':
Make warnings accept a callable for showwarnings instead of
http://hg.python.org/cpython/rev/aaced3dcb858

Committed in 3.3. This cannot be backported as it widens the API and those could lead to subtle incompatibilities.

New changeset eaefb34fc3a1 by Brett Cannon in branch 'default':
Add Misc/NEWS entry and relevant doc change for issue 10271.
http://hg.python.org/cpython/rev/eaefb34fc3a1

Thank you very much for your help