iter8 | Kubernetes release optimizer | Testing library

The problem is, that with the line cache[f'iter{iter}'] = new_lst both the object in the cache dictionary as well as the new_list variable point to the same object. In the next interation then new_lst = lst overwrites it with a new object and now the cache, lst and new_list point to the same object. What you need to do, is to create a 'real' copy of the object. For that you can use the copy package. You should also read about the difference between shallow and deep copy as they are very fundamental and the source of a multitude of problems if not understood correctly.