Thanks, David, for answering the following-up question.
I have figured out the problem. The "zip" object works with "include" as you have anticipated.
The issue that I found is that, in my view, I am zipping the lists in a different function (called "def give_me_zip"). This function returns the zip object. In my view (say "def some_view"), when I call this function, (say "zip_list = give_me_zip(list1, list2, list3)" ), if I pass this "zip_list" to "include", nothing is rendered.
But, if I do the zipping within "some_view" itself, then passing the zip object into "include" works.
I have no idea why, though.
Thanks very much.