Как преобразовать список списков в список чисел (Python)

#python #python_3x #списки

Имеется:

[[1], [2], [3]]


нужно:

[1, 2, 3]

    

Ответы

Ответ 1

>>> a = [[1], [2], [3]]
>>> sum(a, [])
[1, 2, 3]
>>> a = [[1, 2], [3, 4], [5, 6]]
>>> sum(a, [])
[1, 2, 3, 4, 5, 6]


Ответ 2

>>> a = [[1], [2], [3]]
>>> [x for l in a for x in l]
[1, 2, 3]


Ответ 3

Ну или вот так:

from itertools import chain

list(chain.from_iterable(a))


Ответ 4

a = [[1], [2], [3]]
print([i[0] for i in a])


Ответ 5

result = []
for x in [[1], [2], [3]]:
    result.append(x.pop())


или

[x.pop() for x in [[1], [2], [3]]]


Ответ 6

Вариант через from functools import reduce:

from functools import reduce
from operator import add

items = [[1], [2], [3]]
print(reduce(add, items))  # [1, 2, 3]

# Через лябмду
print(reduce(lambda a, b: a + b, items))  # [1, 2, 3]


Ответ 7

еще вариант

outer = [[1,2,3], [4,5,6], [7,8,9]]
new_list = [item for sublist in outer for item in sublist]


получим

[1,2,3,4,5,6,7,8,9]