[Python-3000] Is pickle's persistent_id worth keeping?

[Alexandre Vassalotti]

Hi,

I currently trying to clean up the interface of the pickle module for
Python 3K. So far, I haven't done much, except documenting parts the
pickle stream format.

There's still one thing I still don't understand about pickle,
persistent_id. I haven't found any useful use-cases for it. Using
Google's code search, only Zope (or variant of) seems to have found
some obscure way to use it. (Is there a Python feature Zope doesn't
use? <wink>) Personally, I think persistent_id is just a remnant of
the older protocol, which didn't memoize object.

So, would it be okay to remove it from the next version of the protocol?

-- Alexandre