In every program we have talked about so far, when the program ends, the computer forgets everything that happened in the program. Every variable you created, every string you used, every Boolean, every list—it’s all gone. But what if you want to keep some of the data you generate in a program and save it for when you run the program later? Or maybe you want to save some data so that a different program could use the data you generated.
If you want to keep some information around between runs of a program, you need a way of having what is called persistent data —you want the data to remain ...