On Fri, Sep 2, 2011 at 3:44 AM, Vince <vincent.kni...@gmail.com> wrote: > Dear all, > > If I have a list, how do I obtain the cardinality of the list, the > command Cardinality() doesn't seem to always work. For example, the > following code produces a set ComSet of sets of combinations. > > Rows=3 > RowVector=[2,3,2] > ComSet=[] > for j in range(Columns): > C=Combinations(range(Rows),RowVector[j]) > ComSet.append(C.list()) > show(ComSet)
What's Columns? > However using Cardinality() on ComSet does not seem to work: > > ComSet.Cardinality() > > Basically I am looking for the mathematica command "Length". FYI, most Python and Sage commands start with a lower case. In this case, however, what you're looking for is len(ComSet). If you have an object x, type x-dot-tab to see what methods it supports. > Furthermore how would I be able to map that command on to the elements > of ComSet? Use "list comprehensions" (it's a Python thing). sage: L = [[1, 2, 3], [4, 5]] sage: [len(a) for a in L] [3, 2] -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
