50 ayanamsa systems-- Lahiri, KP Krishnamurti, Raman, Fagan-Bradley, True Chitrapaksha, True Revati, Surya Siddhanta, all Galactic Center variants, Babylonian (Kugler), all Swiss Ephemeris IDs (0-46), ...
Problem Solving with Algorithms and Data Structures using Python by Brad Miller and David Ranum Purely Functional Data Structures by Chris Okasaki [pdf] Sequential and Parallel Data Structures and ...