I am trying to learn how to "zip" lists. To this end, I have a program, where at a particular point, I do the following:

x1, x2, x3 = stuff.calculations(withdataa)

This gives me three lists, x1, x2, and x3, each of, say, size 20.

Now, I do:

zipall = zip(x1, x2, x3)

However, when I do:

print "len of zipall %s" % len(zipall)

I get 20, which is not what I expected. I expected three. I think I am doing something fundamentally wrong.