how can I sort a bunch of lists over multiple fields?

[googleboy]

I'd be just such a newbie; I don't understand why it would matter if I
left the book instance referencing itself....

However these wonderful responses have gotten me a very long way
towards my goal.  I just have a couple of quick questions.

firstly,  I am trying hard to figure out how to create a new file with
the list rather than print to standard out.  I haev done this:

    for book in books:
        print book # just to be sure it works as I expect
        sort1 = open(r'D:\path to\sort1.csv', 'w+')
        print >> sort1, book
        sort1.close()

and this creates the file as I expect, however it creates it populated
with only the information of the final book in the sorted list. I am
guessing I need to figure out how to append as part of this loop,  but
the only info I have found so far suggests this should append by
default....?

Secondly,  I am wondering how I can get a search algorithm that will
search by multiple fields here,  so that I can (as one example) sort
the books out by author and then date,  to present a list of the book
grouped by authors and having each group presented in a chronological
order,   or by author and title, grouping all the books up into authors
presenting each group alphabetically by title.  Or by publisher and
date,  or by publisher and code....

I have tried things like

books.sort(key = operator.attrgetter("author"), key =
operator.attrgetter("title") and
books.sort(key = operator.attrgetter("author", "title")

but they both give errors.

Is this where using cmd functions instead of keys becomes necessary?

Thanks!

googleboy