One-liner to merge lists?

Fri Feb 25 18:04:00 EST 2022

 If you don't like the idea of 'adding' strings you can 'concat'enate:
 >>> items = [[1,2,3], [4,5], [6]]
 >>> functools.reduce(operator.concat, items)
 [1, 2, 3, 4, 5, 6]
 >>> functools.reduce(operator.iconcat, items, [])
 [1, 2, 3, 4, 5, 6]
 The latter is the functional way to spell your for... extend() loop.
 Don't forget to provide the initial value in that case lest you modify
 the input:
 >> functools.reduce(operator.iconcat, items)  # wrong
 [1, 2, 3, 4, 5, 6]
 >>> items
 [[1, 2, 3, 4, 5, 6], [4, 5], [6]]  # oops
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 ====
 Was also thinking about reduce, though this one uses a dunder method:
 from functools import reduce
 d = {1: ['aaa', 'bbb', 'ccc'], 2: ['fff', 'ggg']}
 print(reduce(list.__add__, list(d.values())))