izip_longest {itertools2} | R Documentation |
The resulting iterator aggregates elements from each of the iterables into a list from each iteration. Used for lock-step iteration over several iterables at a time.
izip_longest(..., fill = NA)
... |
multiple arguments to iterate through in sequence |
fill |
the value used to replace missing values when the iterables in
|
Although similar to izip
, missing values are
replaced with fill
if the iterables are of uneven length, and
Iteration continues until the longest iterable is exhausted.
iterator that iterates through each argument in sequence
it <- izip_longest(x=1:3, y=4:6, z=7:9)
iterators::nextElem(it) # list(x=1, y=4, z=7)
iterators::nextElem(it) # list(x=2, y=5, z=8)
iterators::nextElem(it) # list(x=3, y=6, z=9)
it2 <- izip_longest(1:3, 4:8)
iterators::nextElem(it2) # list(1, 4)
iterators::nextElem(it2) # list(2, 5)
iterators::nextElem(it2) # list(3, 6)
iterators::nextElem(it2) # list(NA, 7)
iterators::nextElem(it2) # list(NA, 8)
it3 <- izip_longest(1:2, 4:7, levels(iris$Species), fill="w00t")
iterators::nextElem(it3) # list(1, 4, "setosa")
iterators::nextElem(it3) # list(2, 5, "versicolor")
iterators::nextElem(it3) # list("w00t", 6, "virginica")
iterators::nextElem(it3) # list("w00t", 7, "w00t")