Examples of classes that implement special operators (see reference manual):

Complex.py Complex numbers

Dates.py Date manipulation package by Tim Peters

Dbm.py Wrapper around built-in dbm, supporting arbitrary values

Range.py Example of a generator: re-implement built-in range()

Rat.py Rational numbers

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 -- especially the window

modules are full of them.)