迭代列表中的每两个元素以执行列表 python

Question

I have a list named newList and inside the list there is another list of information with JSON code. I want to iterate every two elements in the newList to do something for those two elements.

ex: if my newList length is 8, I want to able do a for loop or access the 0 and 1 element, do something with the information inside those two elements, then go to 1 and 2 elements and do something with those elements.

My code:

data = np.arange(len(newList))

 def pairwise(iterable):
    a, b = tee(iterable)
    next(b, None)
    return zip(a, b)

  for v, w in pairwise(data):
    print(v, w)

print result:

0 1
1 2
2 3
3 4
4 5
5 6
6 7
7 8
8 9
9 10
10 11
11 12
12 13
13 14
14 15

What I am looking for:

0 1
2 3
4 5
6 7
8 9
10 11
12 13
14 15 

Answer 1

You can create a single iterator and then zip it with itself:

def pairwise(iterable):
    return zip(*[iter(iterable)]*2)

which is similar to:

def pairwise(iterable):
    i = iter(iterable)
    return zip(i, i)

Answer 2

Do you want (0, 1), (1, 2) or (0, 1), (2, 3)? Your question seems to say you want one, and it seems to say you want the other.

Anyway, here's some code for the latter:

#!/usr/local/cpython-3.8/bin/python3


import itertools


def test_data(n):
    # Yes, there's a simpler way of doing this.
    for i in range(n):
        yield i


def two_up(iterable):
    left_iterable, right_iterable = itertools.tee(iterable)
    left_every_other = itertools.islice(left_iterable, 0, None, 2)
    right_every_other = itertools.islice(right_iterable, 1, None, 2)
    for tuple_ in zip(left_every_other, right_every_other):
        yield tuple_


def main():
    it = test_data(10)
    for thing in two_up(it):
        print(thing)


main()