How to check if multiple substrings appear together in a string

Question

strings = ['I have a bird', 'I have a bag and a bird', 'I have a bag']
words = ['bird','bag']

I want to find the string that includes both bird and bag in the list strings, regardless of order. So the result for only the second element in strings should be true and the rest should be false.

The output I want:

False
True
False

words do not necessarily need to be stored in list, and I know that regex could do a similar thing but I would prefer to use other ways than regex because my words are mandarin chinese which requires some complicated use of regex than english.

The nested-for loop solutions are fine but they don't scale well. If you have huge amount of text and your text or query words are related by common prefixes, [this](https://stackoverflow.com/questions/43628742/find-lots-of-string-in-text-python/43629194) may help you. — Cong Ma, Apr 28 '17 at 09:38

score 8 · Answer 1 · answered Apr 28 '17 at 09:21

8

List comprehension will work combined with the all function:

[all([k in s for k in words]) for s in strings]

This results in the following on your example:

[False, True, False]

answered Apr 28 '17 at 09:21

languitar

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3

`[all(word in sentence for word in words) for sentence in strings] ` :-) – qPCR4vir Apr 28 '17 at 09:26

score 2 · Accepted Answer · answered Apr 28 '17 at 09:27

2

strings = ['I have a bird', 'I have a bag and a bird', 'I have a bag']
words = ['bird','bag']


for string in strings:
  stringlist = string.split()
  word1 , word2 = words
  if word1 in stringlist and word2 in stringlist:
    print(True)
  else:
    print(False)

Result

False True False

answered Apr 28 '17 at 09:27

Fuji Komalan

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I now get how things work, thanks! I didn't know I needed to split the strings before I try to find the words within the string. – halo09876 Apr 28 '17 at 09:31

foxyblue · Answer 3 · 2017-04-28T21:42:57.547

1

This is it:

for substring in strings:
    k = [ w for w in words if w in substring ]
    print (len(k) == len(words) )

edited Apr 28 '17 at 21:42

answered Apr 28 '17 at 09:20

foxyblue

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I would prefer this one but it only resulted in false false? – halo09876 Apr 28 '17 at 09:23
Sorry, I didn't understand your initial question - but i've fixed my answer – foxyblue Apr 28 '17 at 09:32

Aakash Goel · Answer 4 · 2017-04-28T10:08:24.790

Use of function all() would be best option here, but point is doing without for loop. Here is solution using map/lambda function.

strings = ['I have a bird', 'I have a bag and a bird', 'I have a bag']
words = ['bird','bag']
map(lambda x: all(map(lambda y:y in x.split(),words)),strings)

output would be:

[False, True, False]

However, Naive Solution is for beginner:

for string in strings:
    count_match=0
    for word in words:
        if word in string.split():
            count_match+=1
    if(count_match==len(words)):
        print "True"
    else:
        print "False"

And output would be :

False
True
False

score 1 · Answer 5 · answered Apr 28 '17 at 12:23

1

For variable number of words, without using the split function.

strings = ['I have a bird', 'I have a bag and a bird', 'I have a bag']
words = ['bird','bag']

 for string in strings:
    print(all(word in string for word in words))

answered Apr 28 '17 at 12:23

nikhalster

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How to check if multiple substrings appear together in a string

5 Answers5