Pluck in Python

Just use a list comprehension in whatever function is consuming uids:

instead of

uids = map(operator.itemgetter("uid"), users)
foo(uids)

do

foo([x["uid"] for x in users])

If you just want uids to iterate over, you don’t need to make a list — use a generator instead. (Replace [] with ().)

For example:

def print_all(it):
    """ Trivial function."""
    for i in it:
        print i

print_all(x["uid"] for x in users)