The dictionary is exactly what I needed. Thanks!
On Sep 3, 3:56 am, Simon King <[email protected]> wrote: > Hi dkrumm, > > On 3 Sep., 09:33, dkrumm <[email protected]> wrote: > > > Is there a data structure in Python that would allow me to do the > > following: > > > I have a list of positive integer pairs, say [[1,2], [1,3], [2,5]]. > > For each pair [i,j] in my list I need to store in memory a number > > c[i,j] > > Indeed, it is just a Python question. I suggest you read something > about Python dictionaries. > > You could not index a Python dictionary by *lists*, because lists are > mutable, and hell breaks if the keys of a dictionary are modified > after creation. But they can be indexed by tuples. > > Hence, you can do: > > sage: L = [(1,2),(3,4),(5,6)] > sage: D = dict(zip(L,range(3))) > sage: D > {(1, 2): 0, (5, 6): 2, (3, 4): 1} > sage: D[3,4] > 1 > > Best regards, > Simon -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
