[Tutor] object orientation

[Alan Gauld]

> to know why we write len(x) instead of x.len() 

There was a thread about this a fw weeks ago 
- either here or comp.lang.python.

I think history is the real answer. When Guido first built Python 
not everything (strings, ints, floats etc) were first class 
objects so making len() a function meant it was more generally 
useful. Nowadays len() could just as well be an object method.

Alan G.