"R. David Murray" wrote:

On Mon, 12 Jun 2000 howardchang@263.net wrote:

...

who can tell me where i can get documents or descriptions about Btree,Intset,IOBtree,OIBtree module

I suspect that the only documentation that you are going to find is the source code <wry grin>.

I can probably answer specific questions; I'm monkeying with an varation that should play better in larger environments. BTree is a broad tree similar to a real B-tree (but it isn't height balanced and the nodes aren't fixed size). It can get compiled and built as a couple of variants optimized for holding integer keys or values as opposed to the generic object key and object value. The common use might be to [untested]: import ZODB import BTree import random bt = BTree.BTree() for i in range(0,100000): r = random.randint(0,100000) bt[r] = i print "Items 5000-5100" print list(bt.items(5000,5100)) Since this example uses integer keys and integer values the BTree form is overkill, since it's storing integer Objects rather than just the integers in the tree. The BTrees play with the persistence engine and form the foundation of most of the cataloging type operations in Zope; since you could, for example, store a BTree with each index key being a keyword and each value being a list of objects containing that keyword.