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

[googleboy]

I didn't think this would be as difficult as it now seems to me.

I am reading in a csv file that documents a bunch of different info on
about 200 books, such as title, author, publisher, isbn, date and
several other bits of info too.

I can do a simple sort over the first field (title as it turns out),
and that is fine as far as it gets:


import string

bookData = open(r'D:\path\to\books.csv', 'r')
sBookData = bookData.read()
lBooks = string.split(sBookData, '\n')

lBooks.sort()
sorted = string.join(lBooks, '\n')
output = open(r'D:\path\to\output.csv', 'w')
output.close()


I really want to be able to sort the list of books based on other
criterium, and even multiple criteria (such as by author, and then by
date.)

I am using python 2.4 and have found this site:

http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/305304

and so I tried doing things like

>>>lBooks.sort(cmp=cmp5)
Traceback (most recent call last):
  File "<interactive input>", line 1, in ?
NameError: name 'cmp5' is not defined

(I was hoping that cmp5 meant it would use the 5th item in the lists to
sort across)

>>> lBooks.sort(key=lambda i:i[4])
Traceback (most recent call last):
  File "<interactive input>", line 1, in ?
  File "<interactive input>", line 1, in <lambda>
IndexError: string index out of range


(I was hoping for similar things)


would you be so kind as to point me in the right direction?

THanks!

googleboy