how to iterate over several lists?

[kj]

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);
}

TIA!

kynn

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