8.8 Saving and restoring data

We save the code we write in text file modules and later import it into other modules or our environment. How can we save data and reload it at another time? There are two straightforward options, one binary and one text.

8.8.1 Pickling

Pickling is a Python-specific way of writing some Python objects and collections to binary files. You can later read them back in and use them. The Python documentation lists the kinds of data we have covered here that can be pickled: [PYL]

• None, True, and False,
• integers, floating-point numbers, and complex numbers,
• strings and byte strings, and
• tuples, lists, sets, and dictionaries containing only “picklable” objects.

If you can pickle something, it is picklable. (Don’t blame me, I didn’t coin the term.)

Let’s reinstate our guitar dictionary from section 3.9.3.

guitars...