This is PADS, a library of Python Algorithms and Data Structures
implemented by David Eppstein of the University of California, Irvine.

The current version of PADS may be found at
<http://www.ics.uci.edu/~eppstein/PADS/>, as individual files or as a
git repository that may be copied by the command line

git clone http://www.ics.uci.edu/~eppstein/PADS/.git

PADS is hereby placed in the public domain; you may use the code in PADS
for any purpose whatsoever.  We make no guarantee of quality,
completeness, correctness, persistence or consistency of APIs, or support.