Python4Kids: New Tutorial – An Awful Pickle

[ Thanks to Brendan Scott for this
link. ]

“So, we know how to save trivia questions to a file,
and how to read them back from a file in the future. Moreover, we
have decided on a particular way of structuring the data which
makes a question. That is, the question is followed by the correct
answer and then a number of incorrect answers. Now we have to
translate between a list (which has a concept of elements), and a
file (which doesn’t). Files are “flat” – which is to say that
they have no sense of structure, they are simply a stream of data.
A file may record all of the characters which are the questions and
answers, but it wouldn’t record the fact that they are a list or,
indeed, that they are any kind of Python object. I was originally
just going to run with this to let you find out about files, but I
have instead decided to introduce a further concept – the
Python pickle!

“pickle is a module which allows you to store Python objects
including their structure. That means after you have pickled an
object to a file, you can later load that object back up from the
file and all the structure associated with that object will be
preserved.”

Complete
Story