Prototype

Make new objects by cloning an existing one

Prototype creates a new object by copying a fully-configured existing one, instead of building it from scratch. When a recurring booking template already has the walker, dog, and price set, cloning it and tweaking just the date is far cheaper than reassembling everything.

Python hands you this for free: copy.copy for a shallow copy, copy.deepcopy when nested objects must be copied too. No clone() method to write.