Tracking down memory leaks?

[dmsbox2000-list1@yahoo.com]

>> I'm not an expert on python internals, and it is possible that they have
>> a way of checking for cases like this.   I think the deepcopy method
>> catches this, but I don't *think* basic garbage collection look for this
>> sort of thing.
>
> deepcopy has nothing to do with garbage collection.
>
> This is where you use deepcopy:
>
> py> a = [2, 4, [0, 1, 2], 8]  # note the nested list
> py> b = a         # b and a both are bound to the same list
> py> b is a        # b is the same list as a, not just a copy
> True
> py> c = a[:]      # make a shallow copy of a
> py> c is a        # c is a copy of a, not a itself
> False
> py> c[2] is a[2]  # but both a and c include the same nested list
> True
>
> What if you want c to include a copy of the nested list? That's where you
> use deepcopy:
>
> py> d = copy.deepcopy(a)
> py> d[2] is a[2]
> False

What I ment is that deepcopy is recursive, and if you have a circular
reference in your data structure a recursive copy will become infinite.
 I think deepcopy has the ability to detect this situation.  So if it
could be detected for deepcopy, I don't see why it could not be
detected for garbage collection purposes.

David