Search code examples
pythonlistpython-itertools

izip_longest on a list of lists

Is there a way to apply izip_longest() to lists inside a list?

If I have

somelist = [[1, 2, 3], "abcd", (4, 5, 6)]

is there a way to do 

izip_longest(somelist[0], somelist[1], ....)
Solution

  • You can unpack the list, with the *, like this

    my_list = [[1, 2, 3], "abcd", (4, 5, 6)]
izip_longest(*my_list)

    For example,

    from itertools import izip_longest

my_list = [[1, 2, 3], "abcd", (4, 5, 6)]
print list(izip_longest(*my_list))

    Output

    [(1, 'a', 4), (2, 'b', 5), (3, 'c', 6), (None, 'd', None)]

    Note: Using list as a variable name will shadow the builtin list function

    If you choose to use a custom replacement value instead of None, you can do it like this

    print list(izip_longest(*my_list, fillvalue = -1))

    Output

    [(1, 'a', 4), (2, 'b', 5), (3, 'c', 6), (-1, 'd', -1)]