On Sat, 2 Jul 2011 17:39:14 +0000, Demetrius Cassidy <dcassid...@gmail.com> wrote: > I have a C++ class which is declared with pure virtual methods, but if I > derive from this class in python and implement the pure virtual methods, I > get an exception: > TypeError: pyvoip.opal.OpalPCSSEndPoint cannot be instantiated or > sub-classed > > My python class is declared as following: > > class PCSSEndPoint(OpalPCSSEndPoint): > def __init__(self): > super(OpalPCSSEndPoint, self).__init__()
That should be super(PCSSEndPoint, self).__init__() > def OnShowIncoming(self, connection): > return True > > def OnShowOutgoing(self, connection): > return True > > def GetMediaFormats(self): > return [] > > > SIP definitions: > > class OpalPCSSEndPoint : OpalLocalEndPoint /Abstract/ > { > > /**Call back to indicate that remote is ringing. > If false is returned the call is aborted. > > The default implementation is pure. > */ > virtual PBoolean OnShowIncoming( > const OpalPCSSConnection & connection /NoCopy/ ///< Connection having event > ) = 0; > > /**Call back to indicate that remote is ringing. > If false is returned the call is aborted. > > The default implementation is pure. > */ > virtual PBoolean OnShowOutgoing( > const OpalPCSSConnection & connection /NoCopy/ ///< Connection having event > ) = 0; > > }; > > Now the base class of OpalPCSSEndPoint is also an ABC, as it derives from > an > ABC but does not re-define the pure virtual function: > > class OpalLocalEndPoint : OpalEndPoint /Abstract/ > { > ... > }; > > class OpalEndPoint /Abstract/ > { > virtual OpalMediaFormatList GetMediaFormats() const = 0; > }; > > I tried removing /Abstract/ from OpalLocalEndPoint, but it made no > difference. Any idea what's wrong in this scenario? The only way this > works, is if I subclass OpalPCSSEndPoint in C++ and then in Python create a > class derived from my OpalPCSSEndPoint subclass. /Abstract/ is the cause of the problem. It doesn't mean that the C++ is an ABC, it means that the class contains other (unspecified) abstract methods. Phil _______________________________________________ PyQt mailing list PyQt@riverbankcomputing.com http://www.riverbankcomputing.com/mailman/listinfo/pyqt