how to iterate over several lists?

Tom sevenbark at
Fri Jun 5 13:20:12 EDT 2009

On Fri, 5 Jun 2009 04:07:19 +0000 (UTC), kj < at>

>Suppose I have two lists, list_a and list_b, and I want to iterate
>over both as if they were a single list.  E.g. I could write:
>for x in list_a:
>    foo(x)
>for x in list_b:
>    foo(x)
>But is there a less cumbersome way to achieve this?  I'm thinking
>of something in the same vein as Perl's:
>for $x in (@list_a, @list_b) {
>  foo($x);

def chain(*args):
  return (item for seq in args for item in seq)

for x in chain(list_a, list_b):

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