>>> def f(a={}): return a
...
>>> x=f()
>>> x[1]=1
>>> print x
{1: 1}
>>> y=f()
>>> print y
{1: 1}On Mar 3, 5:49 pm, ron_m <[email protected]> wrote: > Ah Ok, I was trying to reproduce with a simple program containing a couple > of classes with a main all in one file but it did not exhibit the problem > behaviour. So having the classes in a module is part of the recipe and lists > and dicts are passed around as object references to the container leaving > the contents open to modification.

