I am searching for a middle ground between Python's zip and zip_longest functions (from the itertools module), that exhausts all given iterators, but does not fill in anything. So, for example, it should transpose tuples like so: (11, 12, 13 ), (11, 21, 31, 41), (21, 22, 23, 24), --> (12, 22, 32, 42), (31, 32 ), (13, 23, 43), (41, 42, 43, 44), ( 24, 44) (Spaces added for nicer graphical alignment.) I managed to compose a crude a solution by cleaning out the fillvalues after zip_longest. def zip_discard(*iterables, sentinel = object()): return map( partial(filter, partial(is_not, sentinel)), zip_longest(*iterables, fillvalue=sentinel)) Is there a way to do this without introducing the sentinels to begin with? Can this be improved using yield? Which approach seems most efficient? Continue reading...
