I don't know if there's a ticket, but one way to fix it is to make the following two lines of parent.Parent.__init__
else: category = Category.join((category, Sets().Facades())) into if category is None: category = Sets().Facades() else: if isinstance(category, (list, tuple)): category = Category.join(tuple(category) + (Sets().Facades(),)) else: category = Category.join((category, Sets().Facades())) David On Sun, Aug 19, 2012 at 12:54 PM, Vincent Delecroix <20100.delecr...@gmail.com> wrote: > Hello, > > There is a weirdness in the initialization of Parent with a facade. > Consider the following example > > class MySet(Parent): > def __init__(self): > Parent.__init__(self, category=(FiniteEnumeratedSets(), Monoids())) > > The category of an instance of MySet is just a join of the two > categories. When I add a facade argument to the initialization of > Parent as in > > class MyFacadeSet(Parent): > def __init__(self): > Parent.__init__(self, category=(FiniteEnumeratedSets(), > Monoids()), facade=FreeMonoid(2, 'ab')) > > I got the error "AttributeError: 'tuple' object has no attribute > 'is_subcategory'". It is few lines in Parent.__init__ but I suspect > that some ticket solves the problem yet. Does anybody know what should > I do? > > Best, > Vincent > > -- > -- > To post to this group, send an email to sage-devel@googlegroups.com > To unsubscribe from this group, send an email to > sage-devel+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/sage-devel > URL: http://www.sagemath.org > > > -- -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org