A very common problem in software engineering is optimising out the problem of construction and destruction of objects. I don't necessarily mean objects exclusively in the context of object orientated programming. I mean objects as in data objects, which could be a large array or a struct and so on.

If you don't need objects for a long time it does seem silly to construct an object, initialise it, then destroy it and discard it. Especially as memory allocation can be expensive.

The most common approach to minimising the impact of this is object pools. An object pool is a collection of pre-constructed objects, sometimes even pre-initialised objects. When a program wants to use an object for a short period of time they can check-out an object, configure it to their needs (if necessary), use the object and then check it back into the pool.

Our good friend Randall was talking about how he liked prototype inheritance such as that in JavaScript. He enjoyed how you can add, modify and remove methods from JavaScript classes and have them apply to all object instances.

Amazed as he was, he's now forcing me at gun point to write a post about it!

The first thing you have to understand about Python classes is that all they are is a collection of references to members. Methods are just function pointers that are referenced by the class, not embedded or copied into the class. This is why all methods require that the first parameter be self, the current instance. Instances themselves contain the real state and reference the class. When you invoke a method on the instance it looks up what function to call.