Find occurrences of connecting words in a string with python

Question

I have a text where all the words are tagged with "parts of speech" tags. example of the text here:

What/NOUN could/VERB happen/VERB next/ADJ ?/PUNCT

I need to find all the occurrences where there is a /PUNCT followed by either NOUN , PRON or PROPN - and also count which one occurs the most often.

So one of the answers would appear like this: ?/PUNCT What/NOUN or ./PUNCT What/NOUN

Further on the word "Deal" appears 6 times, and I need to show this by code.

I am not allowed to use NLTK, only Collections.

Tried several different things, but don't really know what to do here. I think I need to use defaultdict, and then somehow do a while loop, that gives me back a list with the right connectives.

Answer 1

Here is a test program that does what you want.

It first splits the long string by spaces ' ' which creates a list of word/class elements. The for loop then check if the combination of PUNCT followed by NOUN, PRON, or PROPN occurs and saves that to a list.

The code is as follows:

from collections import Counter
string = "What/NOUN could/VERB happen/VERB next/ADJ ?/PUNCT What/NOUN could/VERB happen/VERB next/ADJ ?/PUNCT"
words = string.split(' ')

found = []

for n, (first, second) in enumerate(zip(words[:-1], words[1:])):
    first_class = first.split('/')[1]
    second_class = second.split('/')[1]
    if first_class == 'PUNCT' and second_class in ["NOUN", "PRON", "PROPN"]:
        print(f"Found occurence at data list index {n} and {n+1} with {first_class}, {second_class}")
        found.append(f'{words[n]} {words[n+1]}')

To count the words:

words_only = [i.split('/')[0] for i in words]
word_counts = Counter(words_only).most_common()