Python loops and dinamic stacks : I know that the titel is very unspecific, but that`s because I don´t even know right now how to articulate my question. 

My problem is the following:

I want to creat a loop. This loop is supposed to do an iteration. The only thing I need is the last Iteration it does. I was wondering wether I could creat a dinamic stack for that, so that I don´t define a matric before hand, which uses memory. How could I don that?

Thank you for your answers!
