how to match abbreviations with their meaning with regex?

user_14181437 0
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I'm looking for a regex pattern that matches the following string:

Some example text (SET) that demonstrates what I'm looking for. Energy system models (ESM) are used to find specific optima (SCO). Some say computer systems (CUST) are cool. In the summer playing outside (OUTS) should be preferred.

My goal is to match the following:

Some example text (SET)
Energy system models (ESM)
specific optima (SCO)
computer systems (CUST)
outside (OUTS)

The important part is that it's not always exactly three words and their first letter. Sometimes the letters used for the abbreviation are merely contained in the preceding words. That's why I started looking into the positive lookbehind. However, it is constrained by length, which can be worked around by combining it with a positive lookahead. So far I couldn't come up with a robust solution though.

What I've tried so far:

(\b[\w -]+?)\((([A-Z])(?<=(?=.*?\3))(?:[A-Z]){1,4})\)

This works reasonable well but matches include too many words:

Some example text (SET)
Energy system models (ESM)
are used to find specific optima (SCO)
Some say Computer systems (CUST)
In the summer playing outside (OUTS)

I have also tried to use a reference to the first letter of the abbreviation at the start of the first group. That didn't work at all though.

Things I have looked at but didn't find useful:

Useful resources:

regex-lookarounds python regex
2 Answers

I suggest using

import re
def contains_abbrev(abbrev, text):
    text = text.lower()
    if not abbrev.isupper():
        return False
    cnt = 0
    for c in abbrev.lower():
        if text.find(c) > -1:
            text = text[text.find(c):]
            cnt += 1
            continue
    return cnt == len(abbrev)
 
text= "Some example text (SET) that demonstrates what I'm looking for. Energy system models (ESM) are used to find specific optima (SCO). Some say computer systems (CUST) are cool. In the summer playing outside (OUTS) should be preferred. Stupid example(s) Stupid example(S) Not stupid example (NSEMPLE), bad example (Bexle)"
abbrev_rx = r'\b(([A-Z])\w*(?:\s+\w+)*?)\s*\((\2[A-Z]*)\)'
print( [x.group() for x in re.finditer(abbrev_rx, text, re.I) if contains_abbrev(x.group(3), x.group(1))] )

See the Python demo.

The regex used is

(?i)\b(([A-Z])\w*(?:\s+\w+)*?)\s*\((\2[A-Z]*)\)

See the regex demo. Details:

  • \b - word boundary
  • (([A-Z])\w*(?:\s+\w+)*?) - Group 1 (text): an ASCII letter captured into Group 2, then 0+ word chars followed with any 0 or more occurrences of 1+ whitespaces followed with 1+ word chars, as few as possible
  • \s* - 0+ whitespaces
  • \( - a ( char
  • (\2[A-Z]*) - Group 3 (abbrev): same value as in Group 2 and then 0 or more ASCII letters
  • \) - a ) char.

Once there is a match, Group 3 is passed as abbrev and Group 1 is passedas text to the contains_abbrev(abbrev, text) method, that makes sure that the abbrev is an uppercase string and that the chars in abbrev go in the same order as in text, and are all present in the text.

user_38329700

Just regex won't be enough .. looks like you might a python script for this... this should handle all your scenarios:

import re
a="Some example text (SET) that demonstrates what I'm looking for. Energy system models (ESM) are used to find specific optima (SCO). Some say computer systems (CUST) are cool. In the summer playing outside (OUTS) should be preferred.";
b=re.findall("(\((.*?)\))",a)
a=a.replace(".","")
i=a.split(' ')
for c in b:
   cont=0
   m=[]
   s=i.index(c[0])
   l=len(c[1])
   al=s-l
   for j in range(al,s+1):
       if i[j][0].lower() == c[1][0].lower():
            cont=1
       if cont == 1:
            m.append(i[j])
   print(' '.join(m))

Output:

Some example text (SET)

Energy system models (ESM)

specific optima (SCO)

computer systems (CUST)

outside (OUTS)

user_42740850
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