> Tuples or lists for matrix-like functionality? Use lists. Tuples are meant for small immutable sets of things that go together. Lists are more like arrays, and you can assign to one existing element if you want.
One exception, is a short vector is often a tuple like (x, y, z) and you might want to multiply that vector by your matrix. You can convert a tuple to a list with list(aTuple) or back with tuple(aList.) Even better, take a look at numarray (or numpy or scipy or scipy_core.) They all have really nice matrix code and there are C APIs that let you manipulate them. Chances are they do everything you're intending to implement. Immutability example: tup = ("a", "b", "c") tup[1] = "g" Traceback (most recent call last): File "<input>", line 1, in ? TypeError: object does not support item assignment lst = ["a", "b", "c"] lst[1] = "g" lst ['a', 'g', 'c'] -Jim -- http://mail.python.org/mailman/listinfo/python-list