CODEWITHSUNDEEP
pythonlist
RubberDuckProducer
RubberDuckProducer

Reputation: 247

Split the list into multiple sublists heading by 1

Say I have a list like this:

lst = [1, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0,
        1, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0,
        1, 0, 0, 0, 0, 0, 2, 0, 0]

I intended to split it into multiple sub-lists heading by 1:

new_lst = [[1, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0],
           [1, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0],
           [1, 0, 0, 0, 0, 0, 2, 0, 0]]

This is how I render it for now and it worked fine. Is there any simplier way to do it? Like itertools however I couldn't think of how at this moment.

one_list = []

for i, j in enumerate(lst):
    if j == 1:
        one_list.append(i)

new_list = []
for i in range(len(one_list)-1):
    head = one_list[i]
    tail = one_list[i+1]
    new_list.append(flag[head:tail])

Upvotes: 4

Views: 73

Answers (1)

Kraigolas
Kraigolas

Reputation: 5590

more_itertools.split_before will do exactly that

lst = list(more_itertools.split_before(lst, lambda x : x == 1))
# [[1, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0], [1, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0], [1, 0, 0, 0, 0, 0, 2, 0, 0]]

Upvotes: 6

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