string - Python: How to not print comma in last element in a for loop? -

my code iterates on set , print actor's names:

for actor in actorsbymovies():     print actor+",",

the result looks like:

brad pitt, george clooney,

but want detect last element won't print last comma. result should instead:

brad pitt, george clooney

how can that?

print ', '.join(actorsbymovies())

Brande