I agree with Konrad. If you are using the tree data structure for fast access to a large amount of data, use the B-tree portion of bsddb (www.sleepycat.com). Python has bindings to the (old) 1.85 version (somebody might have swigged the newer versions, too). It's faster than any Python program and you get persistency for free. Carlos On Tue, 23 Mar 1999, Konrad Hinsen wrote: Thomas.Sicheritz at molbio.uu.se writes: > What is the best way to implement a tree data structure in pyhton ? That depends on the operations that are to be performed on the data! Konrad. -- ------------------------------------------------------------------------------- Konrad Hinsen | E-Mail: hinsen at cnrs-orleans.fr Centre de Biophysique Moleculaire (CNRS) | Tel.: +33-2.38.25.55.69 Rue Charles Sadron | Fax: +33-2.38.63.15.17 45071 Orleans Cedex 2 | Deutsch/Esperanto/English/ France | Nederlands/Francais -------------------------------------------------------------------------------