Using += in a loop

[Thomas Jensen]

Bill Dandreta wrote:
> Hi Alex,
> 
> On Sat, 27 Jul 2002 20:42:03 GMT, Alex Martelli <aleax at aleax.it>
> wrote:
> 
>>As a nice plus, it's also *WAY, WAY* faster.  A loop with += takes
>>O(N squared) time, joiner.join takes O(N) time, where N is the

[snip]

> I am using the following code structure in some very long (10's of
> thousands of iterations) loops.
> 
> Is there a more efficient way that doesn't use +=?
> 
> Would s5 = '%s,"%s"' % (s5,x[1]) be better?

Probably not (it would still have the O(N squared) charactaristics).
Instead try:

   s5_list = []
   for ...:
     s5_list.append(',"%s"' % x[1])

   s5 = ''.join(s5_list)

-- 
Best Regards
Thomas Jensen
(remove underscore in email address to mail me)