How do I return the index of multiple elements existing in a list in Python?

Question

L=[0,8,5,6,4,5,6,14,8]

I want to be able to return the index of [4,5,6] (returning 4 in this example).

Why are people voting to close? This is a perfectly legitimate question. — MyNameIsKhan, Dec 23 '12 at 03:26
I think the not a real question votes are from people who believe you have 0rovided no example code of yours to compare against. Further a reply from you to someones answer clearly statss your question whereas this shows little to no effort. — Woot4Moo, Dec 23 '12 at 03:33
duplicate of: http://stackoverflow.com/questions/7627548/find-sub-list-inside-a-list-in-python — Chronial, Dec 23 '12 at 03:59

score 2 · Answer 1 · answered Dec 23 '12 at 03:26

2

Here's one way to implement it:

def find_in_list(l, x):
    for i in range(len(l) - len(x) + 1):
        if l[i:i+len(x)] == x:
            return i

answered Dec 23 '12 at 03:26

Mark Byers

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This is what I'm currently doing; is there a built-in Python function that would make this a short one-liner at all? – MyNameIsKhan Dec 23 '12 at 03:26

jackcogdill · Accepted Answer · 2012-12-23T14:19:04.117

1

Use this instead:

' '.join(map(str,L)).index(' '.join(map(str,x)))/2

EDIT: Thanks to isbadawi for noticing the silly mistake, and solilo for pointing out the huge mistake haha

edited Dec 23 '12 at 14:19

answered Dec 23 '12 at 03:33

jackcogdill

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Seems to have the fastest runtime of all suggested solutions, and it is a one-liner – MyNameIsKhan Dec 23 '12 at 03:40
1

`lambda c: str(c)` can be written as just `str` – Ismail Badawi Dec 23 '12 at 03:42
Oh yeah you're right duh – jackcogdill Dec 23 '12 at 03:52
It's just wrong, suppose L = [0, 1, 1], x = [11], x is not in L, and your method will return 1 – Qiang Jin Dec 23 '12 at 07:31
@solilo I think it's fine now – jackcogdill Dec 23 '12 at 14:19

score 1 · Answer 3 · answered Dec 23 '12 at 03:36

1

In [193]: min(i for i in range(len(L)) if L[i:i+len(key)] == key)
Out[193]: 4

In [194]: L=[0,8,5,6,4,5,6,14,8]

In [195]: key=[4,5,6]

In [196]: min(i for i in range(len(L)) if L[i:i+len(key)] == key)
Out[196]: 4

answered Dec 23 '12 at 03:36

inspectorG4dget

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How do I return the index of multiple elements existing in a list in Python?

3 Answers3