Xapian discuss - Jul 2012 - Can not use custom weight scheme with python binding

Hi, I'm trying to use custom weight with python binding.
My test code is like this.

class TinkerWeight(xapian.Weight):
    def __init__(self):
        pass

    def name(self):
        return "Tinker"

    def serialize(self):
        return ""

    def get_sumpart(*args):
        return 1

    def get_maxpart(*args):
        return 1

    def get_sumextra(*args):
        return 0

    def get_maxextra(*args):
        return 0

... ...

enquire.set_weighting_scheme(TinkerWeight())

But is throws this error:
*in method 'Enquire_set_weighting_scheme', argument 2 of type
'Xapian::Weight const &'*

Could anyone help me to solve this? Thanks a lot.

On Tue, Jul 17, 2012 at 05:26:49PM +0800, piglei wrote:
> Hi, I'm trying to use custom weight with python binding.
It's not currently supported.  We had concluded it wasn't possible to,
but I probably found a way to do it.  The story is in this ticket:

http://trac.xapian.org/ticket/401
> Could anyone help me to solve this? Thanks a lot.
As noted in the last comment in #401, this can probably be implemented
using the trick described in http://trac.xapian.org/ticket/554 but
nobody's yet done that yet.  If you want to work on it, a patch would be
great.

Cheers,
    Olly