Or, in the notebook/cell server/cloud, choose "python" from the drop-down menu for system and just do this example in Python! Lots of options.
> Or type > > Integer = int > > to make Sage integers the usual Python integers in that session. > > On Thu, Oct 23, 2014 at 11:54 AM, Volker Braun <[email protected]> > wrote: > > The short answer is that mathematical objects in Sage don't define > addition > > by implementing __add__ and __radd__ by hand. If you want to learn about > > them make sure to not add Sage objects (like Sage integers). E.g. int(1) > + y > > would work. > > > > > > > > On Thursday, October 23, 2014 7:46:02 PM UTC+1, João Alberto Ferreira > wrote: > >> > >> I am running the following Python example from the book "Learning > >> Python", from Mark Lutz and David Ascher, but Sage is returning a > >> TypeError after presenting the correct response. Can anyone explain me > >> why? I've found this very strange. > >> > >> sage: class Commuter: > >> ....: def __init__(self, val): > >> ....: self.val = val > >> ....: def __add__(self, other): > >> ....: print "add", self.val, other > >> ....: def __radd__(self, other): > >> ....: print "radd", self.val, other > >> ....: > >> sage: x = Commuter(88) > >> sage: y = Commuter(99) > >> sage: x + 1 > >> add 88 1 > >> sage: 1 + y > >> radd 99 1 > >> > >> > --------------------------------------------------------------------------- > >> TypeError Traceback (most recent call > >> last) > >> <ipython-input-76-e047f7a3a32a> in <module>() > >> ----> 1 Integer(1) + y > >> > >> > >> > /usr/local/Sagemath/sage-6.3/local/lib/python2.7/site-packages/sage/structure/element.so > > > >> in sage.structure.element.RingElement.__add__ > >> (build/cythonized/sage/structure/element.c:14696)() > >> > >> > >> > /usr/local/Sagemath/sage-6.3/local/lib/python2.7/site-packages/sage/structure/coerce.so > > > >> in sage.structure.coerce.CoercionModel_cache_maps.bin_op > >> (build/cythonized/sage/structure/coerce.c:8323)() > >> > >> TypeError: unsupported operand parent(s) for '+': 'Integer Ring' and > >> '<type 'instance'>' > > > > -- > > You received this message because you are subscribed to the Google > Groups > > "sage-support" group. > > To unsubscribe from this group and stop receiving emails from it, send > an > > email to [email protected]. > > To post to this group, send email to [email protected]. > > Visit this group at http://groups.google.com/group/sage-support. > > For more options, visit https://groups.google.com/d/optout. > > > > -- > William Stein > Professor of Mathematics > University of Washington > http://wstein.org > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
