Hey, I started with this:
factByClass = {} def update(key, x0, x1, x2, x3): x = factByClass.setdefault(key, [ [], [], [], [] ]) x[0].append(x0) x[1].append(x1) x[2].append(x2) x[3].append(x3) update('one', 1, 2, 3, 4) update('one', 5, 6, 7, 8) update('two', 9, 10, 11, 12) print factByClass {'two': [[9], [10], [11], [12]], 'one': [[1, 5], [2, 6], [3, 7], [4, 8]]} I then 'upgraded' to this: def update(key, *args): x = factByClass.setdefault(key, [[], [], [], [] ]) for i, v in enumerate(args): x[i].append(v) Is there a better way? Cheers! -- http://mail.python.org/mailman/listinfo/python-list