having both dynamic and static variables

[Paul Rubin]

Steven D'Aprano <steve+comp.lang.python at pearwood.info> writes:
> but I call that a feature, not a bug. If you want an immutable constant, 
> use a tuple, not a list.

Nope:

    L = ([1,2],[3,4])  # tuple
    L[0].append(5)     # mutate L, in some reasonable sense of "mutate"