CODEWITHSUNDEEP
pythonregex
Superbman
Superbman

Reputation: 861

Python regex to count multiple matched strings within sentences

I'm trying to get counts of patterns generated from a string hello awesome world found in a large text. Patterns are generated by permuting words and replacing one word with * in between. In this example i use only 4 patterns to simplify things. I'm not really familiar with regex so my code doesn't match everything i need yet. I'll probably figure it out soon but i'm not sure if it would scale well when i feed real data.

The questions are how do i fix my code and are there better/faster ways to achieve my goal? Here's my code bellow with explainations.

import re
from collections import Counter


# Input text. Could consist of hundreds of thousands of sentences.
txt = """
Lorèm ipsum WORLD dolor AWESOME sit amèt, consectetur adipiscing elit. 
Duis id AWESOME HELLO lorem metus. Pràesent molestie malesuada finibus. 
Morbi non èx a WORLD HELLO AWESOME erat bibendum rhoncus. Quisque sit 
ametnibh cursus, tempor mi et, sodàles neque. Nunc dapibus vitae ligula at porta. 
Quisque sit amet màgna eù sem sagittis dignissim et non leo. 
Quisque WORLD, AWESOME dapibus et vèlit tristique tristique. Sed 
efficitur dui tincidunt, aliquet lèo eget, pellentesque felis. Donec 
venenatis elit ac aliquet varius. Vestibulum ante ipsum primis in faucibus
orci luctus et ultrices posuere cubilia Curae. Vestibulum sed ligula 
gravida, commodo neque at, mattis urna. Duis nisl neque, sollicitudin nec 
mauris sit amet, euismod semper massa. Curabitur sodales ultrices nibh, 
ut ultrices ante maximus sed. Donec rutrum libero in turpis gravida 
dignissim. Suspendisse potenti. Praesent eu tempor quam, id dictum felis. 
Nullam aliquam molestie tortor, at iaculis metus volutpat et. In dolor 
lacus, AWESOME sip HELLO volutpat ac convallis non, pulvinar eu massa.
"""

txt = txt.lower()

# Patterns generated from a 1-8 word input string. Could also consist of hundreds of 
# thousands of patterns
patterns = [
    'world',
    'awesome',
    'awesome hello', 
    'world hello awesome',
    'world (.*?) awesome'   # '*' - represents any word between
]

regex = '|'.join(patterns)
result = re.findall(regex, txt)
counter = Counter(result)
print(counter)
# >>> Counter({'awesome': 5, 'world': 3})

# For some reason i can't get strings with more than one word to match

# Expected output
found_pattern_counts = {
    'world': 3,
    'awesome': 5,
    'awesome hello': 1, 
    'world hello awesome': 1,
    'world * awesome': 2
}

Upvotes: 1

Views: 130

Answers (2)

EntGriff
EntGriff

Reputation: 875

You didn't use wildcard properly, I fixed it and now it works as you described and now you can create additional function for this operation: 

patterns = [
    'world',
    'awesome',
    'awesome hello', 
    'world hello awesome',
    'world (.*?) awesome'
]


result = {} 
for pattern in patterns:
   rex = re.compile(fr'{pattern}') 
   count = len(rex.findall(txt))   
   result[pattern] = result.get(pattern, 0) + count

print(result)

Upvotes: 1

Auss
Auss

Reputation: 491

You could look into

re.finditer()

Iterators save you a lot of resources if you don't need all the data at once (which you hardly ever do). This way you don't need to hold so much information in memory. Look into this Do iterators save memory in Python?

Upvotes: 0

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