lists <-> tuple

[Jim]

> 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