Python get index of list in list of lists that contains a substring

Question

I have a list that looks like this:

lst = [['Apple Pie', 'Carrot Cake'], ['Steak', 'Chicken']]

I would like to find the index of the list that contains the word ' Carrot', so in this case, the output should be 0

I have tried to make a function

def find_index(l, c):
    for i, v in enumerate(l):
        if c in v:
            return i

res = find_index(lst, 'Carrot')

but this does not work since it looks for items in the list.

Can anyone help me to retreive the index of the list that contains 'Carrot'?

Thanks!

Edit: I received multiple answers for this question, and they all worked. so I decided to time them and accept the fastest one as the answer. here are the results:

import timeit

lst = [['Apple Pie', 'Carrot Cake'], ['Steak', 'Chicken']]


def find_index(l,c):
    for i,v in enumerate(l):
        for j in v:
            if c in j:
                return i

print(timeit.timeit('%s'%(find_index(lst,'Carrot Cake'))))

def find_index(l, c):
    for i, v in enumerate(l):
        if any(c in x for x in v):
            return i

print(timeit.timeit('%s'%(find_index(lst,'Carrot Cake'))))

def function(list_contains,word_to_know):
    for x in list_contains:
        for y in x:
            if word_to_know in y:
                return list_contains.index(x)

print(timeit.timeit('%s'%(function(lst,'Carrot Cake'))))

def index_of_substr(l, substr):
    for i, inner_list in enumerate(l):
        for text in inner_list:
            if substr in text:
                return i

    return -1

print(timeit.timeit('%s'%(function(lst,'Carrot Cake'))))



0.005458000000000001
0.005462599999999998
0.005485600000000004
0.0054621000000000045

Does the any() function help?

Barmar
– Barmar

2021-08-25 20:20:21 +00:00
Commented Aug 25, 2021 at 20:20 — Barmar
– Barmar, Commented Aug 25, 2021 at 20:20

Twfyq Bhyry · Accepted Answer · 2021-08-25 20:32:38Z

3

use this function it will print the index

lst = [['Apple Pie', 'Carrot Cake'], ['Steak', 'Chicken']]
def function(list_contains,word_to_know):
    for x in list_contains:
        for y in x:
            if word_to_know in y:
                return list_contains.index(x)
print(function(lst,"Carrot"))

edited Aug 25, 2021 at 20:32

answered Aug 25, 2021 at 20:24

Twfyq Bhyry

1801 silver badge14 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Suneesh Jacob Over a year ago

This is definitely a great answer, but it wouldn't return 0 if print(function(lst,"Carrot")) is entered.

Twfyq Bhyry Over a year ago

yes, let me edit it and i will make it check if the word is in the word that in the list

Suneesh Jacob · Accepted Answer · 2021-08-25 20:23:46Z

1

You can use something like this:

def find_index(l,c):
    for i,v in enumerate(l):
        for j in v:
            if c in j:
                return i
res = find_index(lst, 'Carrot')

answered Aug 25, 2021 at 20:23

Suneesh Jacob

8041 gold badge7 silver badges15 bronze badges

Comments

kindall · Accepted Answer · 2021-08-25 20:29:24Z

1

You can use any() with a generator expression to determine whether any item in a sublist contains the target string, then return that sublist's index if so.

def find_index(l, c):
    for i, v in enumerate(l):
        if any(c in x for x in v):
            return i

answered Aug 25, 2021 at 20:29

kindall

185k36 gold badges291 silver badges321 bronze badges

Comments

ronpi · Accepted Answer · 2021-08-25 20:52:43Z

Well in the question you mention that you know you are only looking at the first level of the list. So in fact you are trying to match a str to a list which will always give you False. You need to make another iteration over each of the inner lists.

In the following code I made a few modifications to make it a bit more readable:

names of variables are better to have a meaning, especially when there are multiple variables involved.
The return of the function is -1 if no match was found, which is a more common convention than returning None, but of course it is OK to return None as well.

def index_of_substr(l, substr):
    for i, inner_list in enumerate(l):
        for text in inner_list:
            if substr in text:
                return i

    return -1

lst = [['Apple Pie', 'Carrot Cake'], ['Steak', 'Chicken']]
res = index_of_substr(lst, 'Carrot')
print(res)

and the output is 0 of course.

Collectives™ on Stack Overflow

Python get index of list in list of lists that contains a substring

4 Answers 4

2 Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

2 Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related