mooremathewl at gmail.com writes: >>>> x = [1, 2, 3] .. >>>> y > ['insertme', 1, 'insertme', 2, 'insertme', 3] def ix(prefix, x): for a in x: yield prefix yield a y = list(ix('insertme', x)) ================ from itertools import * y = list(chain.from_iterable(izip(repeat('insertme'), x))) ================ etc.