Union of multiple sets in python

Question

The itertools module makes short work of this problem:

>>> from itertools import chain
>>> list(set(chain.from_iterable(d)))
[1, '41', '42', '43', '40', '34', '30', '44']

Another way to do it is to unpack the list into separate arguments for union():

>>> list(set().union(*d))
[1, '41', '42', '43', '40', '34', '30', '44']

The latter way eliminates all duplicates and doesn’t require that the inputs first be converted to sets. Also, it doesn’t require an import.