Author ncoghlan
Recipients Alexander.Belopolsky, Christophe Simonis, anacrolix, belopolsky, eckhardt, ironfroggy, jackdied, jcea, ncoghlan, r.david.murray, rhettinger, ssadler
Date 2013-10-24.10:33:01
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Message-id <1382610781.43.0.10906696951.issue4331@psf.upfronthosting.co.za>
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To clarify the current state of this:

- I'm still in favour of adding this feature for Python 3.4
- a suitable patch is still needed, as the currently attached patches modify the existing functools.partial object, rather than adding a separate "partialmethod" API
- a Python implementation would be fine

The following prototype should work as a starting point to be elaborated into a full patch with docs and tests:

class partialmethod(functools.partial):
    def __get__(self, obj, cls):
        if obj is None:
            return self
        return functools.partial(self.func,
                                 *((obj,) + self.args),
                                 **self.keywords)
    def __call__(*args, **kwds):
        self, *args = args
        call_kwds = {}
        call_kwds.update(self.keywords)
        call_kwds.update(kwds)
        return self.func(self,
                         *(self.args + args),
                         **call_kwds)

class C:
    def example(self, *args, **kwds):
        print(self, args, kwds)
    fails = functools.partial(example, 1, 2, 3, x=1)
    works = partialmethod(example, 1, 2, 3, x=1)

>>> C().fails()
1 (2, 3) {'x': 1}
>>> C().works()
<__main__.C object at 0x7f91cefeea90> (1, 2, 3) {'x': 1}
>>> C().fails(4, 5, 6)
1 (2, 3, 4, 5, 6) {'x': 1}
>>> C().works(4, 5, 6)
<__main__.C object at 0x7f91cefeea10> (1, 2, 3, 4, 5, 6) {'x': 1}
History
Date User Action Args
2013-10-24 10:33:01ncoghlansetrecipients: + ncoghlan, rhettinger, jcea, belopolsky, ironfroggy, jackdied, Christophe Simonis, ssadler, eckhardt, r.david.murray, Alexander.Belopolsky, anacrolix
2013-10-24 10:33:01ncoghlansetmessageid: <1382610781.43.0.10906696951.issue4331@psf.upfronthosting.co.za>
2013-10-24 10:33:01ncoghlanlinkissue4331 messages
2013-10-24 10:33:01ncoghlancreate