how to check if a substring exist in the list having several sublists?

Question

Let's say I have a list such as:

example_of_list = [[['aaaa'],['bbbb'],['cccc']], [['aabsd'],['fdwewd'],['dsfss']], [['sssss'],['ddddd'],['fffff']]]

And I want to check if my_list contains a substring

sub_sting = 'aaa'

So, In that case, this will give 'True' because I have 'aaaa' on the list as a sublist.

How to check this thing?

I already considered 'in' or 'str.contains', but it seems it doesn't give a proper response.

It will raise `NameError` because `aaaa`, `bbbb` and so forth is not defined variables. I guess you meant for them to be strings correct? — Hampus Larsson, Apr 17 '20 at 12:45

score 2 · Accepted Answer · answered Apr 17 '20 at 12:57

Here is a possible solution:

from itertools import chain

def contains(lst, substr):
    return any(substr in s for s in chain(*chain(*lst)))

You can use the function in this way:

lst = [[['aaaa'], ['bbbb'], ['cccc']],
       [['aabsd'], ['fdwewd'], ['dsfss']],
       [['sssss'], ['ddddd'], ['fffff']]]
substr = "aaa"

print(contains(lst, substr)) # True

score 1 · Answer 2 · answered Apr 17 '20 at 12:48

You could flatten the list, then iterate through it. I got the flatten function from What is the fastest way to flatten arbitrarily nested lists in Python?

example_list = [[['aaaa'],['bbbb'],['cccc']], [['aabsd'],['fdwewd'],['dsfss']], [['sssss'],['ddddd'],['fffff']]]

def flatten(container):
    for i in container:
        if isinstance(i, (list,tuple)):
            for j in flatten(i):
                yield j
        else:
            yield i

new_list = list(flatten(example_list))
for elem in new_list:
    if ('aaa' in elem):
        print(elem)

how to check if a substring exist in the list having several sublists?

2 Answers2