See the first answer: http://stackoverflow.com/questions/83983/why-isnt-the-len-function-inherited-by-dictionaries-and-lists-in-python http://stackoverflow.com

See the first answer: http://stackoverflow.com/questions/83983/why-isnt-the-len-function-inherited-by-dictionaries-and-lists-in-python http://stackoverflow.com/questions/83983/why-isnt-the-len-fu...