Does it force the whole file to be executed? I mean jupyter notebooks for machine learning e.g. also profit from state, because to work fast you often really d

Does it force the whole file to be executed? I mean jupyter notebooks for machine learning e.g. also profit from state, because to work fast you often really don't want to recalculate something that took half an hour. (If it takes hours I guess you should store it to a file anyways...)