Find the sentence’s index (sentences in a list) of a specific word in Python

Question

i currently have a file that contains a list that is looks like

example = ['Mary had a little lamb' , 
       'Jack went up the hill' , 
       'Jill followed suit' ,    
       'i woke up suddenly' ,
       'it was a really bad dream...']

I would like to find the index of the sentence with the word “woke” by example. In this example the answer should be f(“woke”)=3. F is a function.

I tried to tokenize each sentence to first find the index of the word like that:

>>> from nltk.tokenize import word_tokenize
>>> example = ['Mary had a little lamb' , 
...            'Jack went up the hill' , 
...            'Jill followed suit' ,    
...            'i woke up suddenly' ,
...            'it was a really bad dream...']
>>> tokenized_sents = [word_tokenize(i) for i in example]
>>> for i in tokenized_sents:
...     print i
... 
['Mary', 'had', 'a', 'little', 'lamb']
['Jack', 'went', 'up', 'the', 'hill']
['Jill', 'followed', 'suit']
['i', 'woke', 'up', 'suddenly']
['it', 'was', 'a', 'really', 'bad', 'dream', '...']

But I don’t know how to finally get the index of the word and how to link it to the sentence’s index. Does someone know how to do that?

Answer 1

You can iterate over each string in the list, split on white space, then see if your search word is in that list of words. If you do this in a list comprehension, you can return a list of indices to the strings that satisfied this requirement.

def f(l, s):
    return [index for index, value in enumerate(l) if s in value.split()]

>>> f(example, 'woke')
[3]
>>> f(example, 'foobar')
[]
>>> f(example, 'a')
[0, 4]

If you prefer using the nltk library

def f(l, s):
    return [index for index, value in enumerate(l) if s in word_tokenize(value)]

Answer 2

for index, sentence in enumerate(tokenized_sents):
    if 'woke' in sentence:
        return index

For all the sentences:

return [index for index, sentence in enumerate(tokenized_sets) if 'woke' in sentence]

Answer 3

If the requirement is to return the first sentence with the occurence of that word you can use something like -

def func(strs, word):
    for idx, s in enumerate(strs):
        if s.find(word) != -1:
            return idx
example = ['Mary had a little lamb' , 
       'Jack went up the hill' , 
       'Jill followed suit' ,    
       'i woke up suddenly' ,
       'it was a really bad dream...']
func(example,"woke")