Examples of classes that implement special operators (see reference manual):
Complex.py Complex numbers
Dates.py Date manipulation package by Tim Peters
Range.py Example of a generator: re-implement built-in range()
Rev.py Yield the reverse of a sequence
Vec.py A simple vector class
bitvec.py A bit-vector class by Jan-Hein B\"uhrman
(For straightforward examples of basic class features, such as use of
methods and inheritance, see the library code.)
