"Nikhil" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] | Then why to have __len__() internal method at all when the built-in | len() is faster?
Nearly all syntax constructions and builtin functions are implemented by calling one or another of the __special__ methods. This is what makes Python code so generic and plugging your own classes into the system so easy. For example, collection[key] = value is implemented by calling collection.__setitem__(key, value). When you define a class with that method, that syntax will work with its instances just the same as for builtin classes. Similarly, a+b is implemented by calling a.__add__(b). So if a class defines __add__, you can 'add' its instances (whatever 'add' means for that class) with '+'. (The fact that an *implementation* may followup the 'as if' rule and optimize operations for certain classes by combining steps does not negate the *language* rules given above.) tjr -- http://mail.python.org/mailman/listinfo/python-list
