Checking if a lists' items are in the same order in another list

Question

I have a list, say [1, 5, 2, 6, 2, 5, 1].
The items in this list are in the same order in this list: [4, 1, 5, 2, 6, 2, 5, 1, 6, 2, 3]

What's an easy way finding out if a 1-nested lists' items are in the same order in another 1-nested lists' items?

http://stackoverflow.com/questions/3847386/testing-if-a-list-contains-another-list-with-python — pcalcao, Jun 25 '12 at 15:50
It should be trivial then to adjust the answer to the other question then. — jgritty, Jun 25 '12 at 15:54
@beary605 You get a boolean, False if it doesn't contain the list, and a list otherwise, should be trivial to make that True — NominSim, Jun 25 '12 at 15:55
Do the items of the first list have to appear consecutively in the second list? — interjay, Jun 25 '12 at 15:58
@DSM: My answer is horribly wrong and I have deleted it. Thanks Thanks for pointing it out. — pyfunc, Jun 25 '12 at 20:30

score 4 · Accepted Answer · answered Jun 25 '12 at 16:02

After looking at the question I wrote this. Unlike some of the others that assume that the elements in the first array must occur in the second contiguously, this does not.

def in_order(a,b):
    j = iter(b)
    for i in a:
        while True:
            try:
                j_ = j.next()
            except StopIteration:
                return False
            if i == j_:
                break
    return True

The OP's example:

a = [1, 5, 2, 6, 2, 5, 1]
b = [4, 1, 5, 2, 6, 2, 5, 1, 6, 2, 3]
print in_order(a,b)

prints: True

D: Elegant answer. I assumed that elements were supposed to occur contiguously — pyfunc, Jun 25 '12 at 16:03

score 0 · Answer 2 · answered Jun 25 '12 at 16:51

0

size = len(needle)
any(needle == haystack[i:i+size] for i in range(len(haystack) - size + 1))

answered Jun 25 '12 at 16:51

Karl Knechtel

62,466
11
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score -1 · Answer 3 · edited May 23 '17 at 12:04

-1

Just modify the top answer from here: Testing if a list contains another list with Python

edited May 23 '17 at 12:04

Community

1
1

answered Jun 25 '12 at 15:54

jgritty

11,660
3
38
60

2

I am adding +1 for simple fact that when downvoting people should provide a comment that should be helpful to the user – pyfunc Jun 25 '12 at 15:58
1

@pyfunc I downvoted for copy/paste from duplicate answer already posted – NominSim Jun 25 '12 at 16:00
2

If this answer solves the question (which isn't clear until the OP clarifies it), then the question should be marked as a duplicate of the other one rather than copy/pasting the answer from there. – interjay Jun 25 '12 at 16:01
@NominSim: Sorry. But we should provide the comment. Thanks for coming back. Yeah, we do not want repeated answers in SO. We should just point out in that case – pyfunc Jun 25 '12 at 16:02
I have flagged the question as a duplicate... – jgritty Jun 25 '12 at 16:04
@pyfunc I actually wasn't sure of the etiquette of copy/pasting an answer from a duplicate question so went to meta to check before coming back to explain the DV. – NominSim Jun 25 '12 at 16:06

Checking if a lists' items are in the same order in another list

3 Answers3