On Sat, Jul 28, 2012 at 7:12 PM, Francesco Loffredo <f...@libero.it> wrote: > > My bad, now I'll RTFM again and I will study very carefully the operator and > itertools modules.
I forgot to mention a gotcha about groupby's implementation. The grouby object and the yielded _grouper objects share a single iterator. Here's a (somewhat contrived) example of a mistake: >>> groups = groupby(sorted(data, key=keyfunc), keyfunc) >>> groups = list(groups) #DON'T DO THIS >>> groups [((0, '3eA', 'Dupont', 'Juliette'), <itertools._grouper object at 0xb74734ec>), ((1, '3eA', 'Pop', 'Iggy'), <itertools._grouper object at 0xb74735cc>)] >>> list(groups[0][1]) #EMPTY [] >>> list(groups[1][1]) #ONLY THE LAST ITEM [(1, '3eA', 'Pop', 'Iggy', 5, 40.5, 60.0)] _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
