Comment by jonjacky

Peter Norvig's examples. They are quite short and include much explanation in addition to code. They also include tests and benchmarking code.

http://norvig.com/lispy.html http://norvig.com/lispy2.html (Lisp interpreter)

http://www.norvig.com/spell-correct.html (Spelling corrector)

http://norvig.com/sudoku.html (Sudoku solver)

Also his online course Design of Computer programs includes many short, well-explained Python examples:

https://www.udacity.com/wiki/cs212