"Thomas Scrace" <t.scr...@gmail.com> wrote
class with attributes like name, artist, year etc. However, I am at a loss as to how to save these instances so that they can be retrieved the next time I run the program. I assume I need to write them to a file somehow,
That's one way and you can find an example and some advice on how to handle subclassing in the OOP topic of my tutor.
You can also pickle them or even use shelve for random access retrieval later (see the pickle and shelve module docs)
If you have lots of CDs - like thousands! - you might be better off with a database because then you can do sophisticated searches. But OTOH iTunes works pretty well just using a folder structure! :-)
I am sure this has an obvious and easy answer but I just cannot find it anywhere!
Actually no. Saving and retrieving object instances (known as persisting objects in OOP speak) was one of the biggest challenges facing the OOP paradigm when it got started in the real world. Many different solutions have evolved from flat text files to dedicated Object databases, and everyting in between, but it remains a task frought with difficulty, especially on large scale projects.
For simpler programs things like Pickle and Shelve are probably the simplest and best solutions. HTH, -- Alan Gauld Author of the Learn to Program web site http://www.alan-g.me.uk/ _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
