The Python Oracle

How to check if a string is a substring of items in a list of strings

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Chapters
00:00 Question
00:31 Accepted answer (Score 1302)
00:58 Answer 2 (Score 220)
01:22 Answer 3 (Score 100)
01:43 Answer 4 (Score 94)
02:09 Thank you

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Full question
https://stackoverflow.com/questions/4843...

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Tags
#python #string #list

#avk47



ACCEPTED ANSWER

Score 1372


To check for the presence of 'abc' in any string in the list:

xs = ['abc-123', 'def-456', 'ghi-789', 'abc-456']

if any("abc" in s for s in xs):
    ...

To get all the items containing 'abc':

matching = [s for s in xs if "abc" in s]



ANSWER 2

Score 238


Just throwing this out there: if you happen to need to match against more than one string, for example abc and def, you can combine two comprehensions as follows:

matchers = ['abc','def']
matching = [s for s in my_list if any(xs in s for xs in matchers)]

Output:

['abc-123', 'def-456', 'abc-456']



ANSWER 3

Score 107


Use filter to get all the elements that have 'abc':

>>> xs = ['abc-123', 'def-456', 'ghi-789', 'abc-456']
>>> list(filter(lambda x: 'abc' in x, xs))
['abc-123', 'abc-456']

One can also use a list comprehension:

>>> [x for x in xs if 'abc' in x]



ANSWER 4

Score 20


This is quite an old question, but I offer this answer because the previous answers do not cope with items in the list that are not strings (or some kind of iterable object). Such items would cause the entire list comprehension to fail with an exception.

To gracefully deal with such items in the list by skipping the non-iterable items, use the following:

[el for el in lst if isinstance(el, collections.Iterable) and (st in el)]

then, with such a list:

lst = [None, 'abc-123', 'def-456', 'ghi-789', 'abc-456', 123]
st = 'abc'

you will still get the matching items (['abc-123', 'abc-456'])

The test for iterable may not be the best. Got it from here: In Python, how do I determine if an object is iterable?