Terminology matching in text

Question

I have a list of terms as below:

a   
abc
a abc
a a abc
abc

I want to match the terms in text and changes their name as "term1, term2". But I want to find the longest match as the correct match.

Text: I have a and abc maybe abc again and also a a abc.
Output: I have term1 and term2 maybe term2 again and also a term3.

So far I used the code below but it does not find the longest match:

for x in terms:
    if x in text:
       do blabla

Answer 1

You can use re.sub

import re

words = ["a", 
"abc",
"a abc",
"a a abc"
]

test_str = "I have a and abc maybe abc again and also a a abc."

for word in sorted(words, key=len, reverse=True):
    term = "\1term%i\2" % (words.index(word)+1)
    test_str = re.sub(r"(\b)%s(\b)"%word, term, test_str)

print(test_str)

It will get your “expect” result (you made a mistake in the example)

Input: I have a and abc maybe abc again and also a a abc.
Output: I have term1 and term2 maybe term2 again and also term4.

Answer 2

or using a re.sub replace function:

import re

text = 'I have a and abc maybe abc again and also a a abc'
words = ['a', 'abc', 'a abc', 'a a abc']
regex = re.compile(r'\b' + r'\b|\b'.join(sorted(words, key=len, reverse=True)) + r'\b')


def replacer(m):
    print 'replacing : %s' % m.group(0)
    return 'term%d' % (words.index(m.group(0)) + 1)

print re.sub(regex, replacer, text)

result:

replacing : a
replacing : abc
replacing : abc
replacing : a a abc
I have term1 and term2 maybe term2 again and also term4

or use an anonymous replacer:

print re.sub(regex, lambda m: 'term%d' % (words.index(m.group(0)) + 1), text)