[ Thanks to Brendan Scott for this link. ]
“Well, so far we’ve learnt about storing data (either flat in
file, or as an object which Python does in pickles which are also
data in files, but with some structure) but we don’t know anything
about storing the code we are typing. This means that we need to go
through the tedium of typing stuff in all the time (or cutting and
pasting I guess). It is especially tedious when we mistype
something.“In order to do some more complex things in Python we really
need to be able to store our code somewhere so that typing mistakes
we make don’t mean we have to re-type the whole kit and kaboodle.
We could, if we really wanted to, open a file from within our
Python prompt and write code to the file (as a flat file):”