iterating through humongously large key lists!!

[Alex Martelli]

"Mark blobby Robinson" <m.1.robinson at herts.ac.uk> wrote in message
news:3AE706FE.719B091F at herts.ac.uk...
> I needed a non-destructive method so popitem was not a viable option, but
I

In many cases it should not be a problem to 'restore' into _another_
dictionary.  Or do you have many references to the starting dict
which it would be a problem to update...?  Then you can do the
same trick again -- sure, it's gonna be slower, but...

The general idea would be:

newdic = {}
while len(oldict):
    key, value = oldict.popitem()
    process(key, value)
    newdic[key] = value

and now in newdic you have all you earlier had in oldict, and may
pour it back if need be.  Of course, not thread-safe, not fastest, &c,
but still it may be useful.


Alex