On Thu, 16 Apr 2009 12:26:17 -0600 (MDT), Neil Birkbeck <birkb...@cs.ualberta.ca> wrote: > In older versions of sip (4.7.3), I have used __setitem__, __getitem__ to
> access/set elements from multidimensional quantities of a wrapped c++ > object that uses operator()(int,int). For example, the following sip code > used to work fine > > class A { > int operator()(int x,int y) const; > > int __getitem__(int x,int y) const; > %MethodCode > ... > %End > > void __setitem__(int x,int y, int val) const; > %MethodCode > ... > %End > }; > >>From the ChangeLog this feature seemed to have been removed (in a related > mailing list post, it was reported that the above usage was a bug > http://article.gmane.org/gmane.comp.python.pyqt-pykde/12342/match=sip+__setitem__). > > With the new checking (sip 4.7.9, possibly earlier), the above code will > now give an error (e.g., sip: A.sip:18: Incorrect number of arguments to > Python slot). The previous mailing list post > (http://thread.gmane.org/gmane.comp.python.pyqt-pykde/12342) suggested to > either not use __setitem__/__getitem__ for this purpose or to use a tuple. > > I updated my code and the tuples work fine for __getitem__, but I cannot > seem to get the tuple to work for __setitem__. > > For example, > > A.sip: > > class A { > int __getitem(int x,int y); > %MethodCode > //This is just a dummy, actually parse the tuple and extract indices... > %End > > void __setitem__(SIP_PYOBJECT, SIP_PYOBJECT); > %MethodCode > //Do something here.... > %End > }; > > Python test: > from A import A > a = A(10,10) > # Getting works fine, no error parsing arguments > b = a[0,0] > b = a[0] > > # Setting works with anything but tuple > a[0] = 1 # Works fine > a[[1,2]] = 1 # Also works, but is not really a desired syntax > a[0:5] = 1 # Works, would check for this when parsing args. > a[(0,1)] = 1 # Error: "TypeError: too many arguments to A.__setitem__(), 2 > at most expected" > a[0,1] = 1 # Same error > tup = (0,1) > a[tup] = 1 # Same error > > The tuple always gets unpacked into more than one argument for __setitem__ > and causes the TypeError, which happens before any of the sip %MethodCode > can be called. > > Looking at the generated code for the __setitem__, the parsing of args > looks something like: > sipParseArgs(&sipArgsParsed,sipArgs,"P0P0",&a0,&a1) > > On the other hand, the parsing of args for __getitem__ seems to work due > to the single arg format of "1P0". Manually editing the generated code to > return the args packed into a single tuple (including the set value) like > __getitem__ works but is not a satisfying solution. > > Changing the function signature of __setitem__ to take a SIP_PYTUPLE as > the first argument also does not help, although it does change the > sipParseArgs format to "TP0" (e.g., > sipParseArgs(&sipArgsParsed,sipArgs,"TP0",&PyTuple_Type,&a0,&a1)). I > suspect this call would succeed if there was a way to make sipParseArgs > put the first n-1 sipArgs into a0 and the last argument into a1. > > The parsing of arguments for other methods with similar signature, e.g., > "void afunc(SIP_PYOBJECT, SIP_PYOBJECT)", does indeed accept stuff like > afunc((1,2), 0), so the problem appears to be with __setitem__. > > I could be doing something wrong as no one else appears to be having this > problem. If not, is there a some other way to force the argument parsing > to put the first args into a tuple? Or is there a way to do it by hand > (like a NoArgParser for member functions)? Currently, I modified the > sip source (in sipgen/parser.c:findFunction, line 7642, {"__setitem__", > "setitem_slot, TRUE, -1}) to not check the # of arguments to > __setitem__/__getitem__. For the time being, this gives the behaviour of > the older version, so that I can remain using my old sip files (like the > beginning of this post). Try tonight's SIP snapshot. Use __setitem__(SIP_PYTUPLE, SIP_PYOBJECT) and then unpack the tuple as you are in your __getitem__. Thanks, Phil _______________________________________________ PyQt mailing list PyQt@riverbankcomputing.com http://www.riverbankcomputing.com/mailman/listinfo/pyqt