[Python-authors] Introduction and a Question

[Marty Alchin]

Hello all,

I'm an author working with Apress on my second title, Pro Python. It
expands on the Python-level chapter I included in my first title, Pro
Django, which received overwhelmingly positive feedback. Basically,
I'm writing for people who are already familiar with Python, but
haven't looked into some of its more advanced features, like
decorators, magic methods, metaclasses and the like. I'm trying to
focus heavily on examples throughout, finishing up with a complete
build-up of a Django-esque declarative framework for processing CSV
files.

One of the main questions I find myself asking, though, is how much
should I repeat from other works? I don't want to rewrite the wheel,
but I'm having trouble drawing the line. For example, chapter 2 of Pro
Django covered my Python features, focusing mostly on decorators and
metaclasses. I obviously want to cover those same topics in Pro
Python, but I tried very hard to expand on them in much greater
detail--particularly with regard to the examples--so that it wasn't a
direct copy. I also included a really basic plugin framework I wrote
up on my blog a couple years ago, with some added features and a whole
new write-up.

The frustrating thing about doing this is that I feel like I'm torn
between copying something that's already available and throwing away
something that's really good. Neither of them seems like a good way to
go, so the answer must be somewhere in the middle, but I'm having a
lot of trouble finding it. Is it enough to rewrite the description of
a piece of code, so that it's perhaps more clear or more relevant to
the audience at hand? Or is the author expected to expand on the code
itself in some way, offering up some unique value (feature?
optimization? simplification?) that wasn't available in the original?

-Marty