regex whole string match between numbers


I want to extract a whole word from a sentence.
Thanks to this answer,

import re

def findWholeWord(w):
    return re.compile(r'b({0})b'.format(w), flags=re.IGNORECASE).search

I can get whole words in cases like:

findWholeWord('thomas')('this is Thomas again')   # -> <match object>
findWholeWord('thomas')('this is,Thomas again')   # -> <match object>
findWholeWord('thomas')('this is,Thomas, again')  # -> <match object>
findWholeWord('thomas')('this is.Thomas, again')  # -> <match object>
findWholeWord('thomas')('this is ?Thomas again')  # -> <match object>

where symbols next to the word don’t bother.

However if there’s a number it doesn’t find the word.

How should I modify the expression to match cases where there’s a number next to the word? Like:

findWholeWord('thomas')('this is 9Thomas, again')
findWholeWord('thomas')('this is9Thomas again')
findWholeWord('thomas')('this is Thomas36 again')
Asked By: LRD



You may use this code:

import re

def findWholeWord(w):
    return re.compile(r'(?:d+{0}|{0}d+|b{0}b)'.format(w), flags=re.I).search

print ( findWholeWord('thomas')('this is 9Thomas, again') )
print ( findWholeWord('thomas')('this is9Thomas again') )
print ( findWholeWord('thomas')('this is Thomas36 again') )
print ( findWholeWord('thomas')('this is Thomas again') )
print ( findWholeWord('thomas')('this is,Thomas again') )
print ( findWholeWord('thomas')('this is,Thomas, again') )
print ( findWholeWord('thomas')('this is.Thomas, again') )
print ( findWholeWord('thomas')('this is ?Thomas again') )
print ( findWholeWord('thomas')('this is aThomas again') )


<re.Match object; span=(8, 15), match='9Thomas'>
<re.Match object; span=(7, 14), match='9Thomas'>
<re.Match object; span=(8, 16), match='Thomas36'>
<re.Match object; span=(8, 14), match='Thomas'>
<re.Match object; span=(8, 14), match='Thomas'>
<re.Match object; span=(8, 14), match='Thomas'>
<re.Match object; span=(8, 14), match='Thomas'>
<re.Match object; span=(9, 15), match='Thomas'>

(?:d+{0}|{0}d+|b{0}b) will match given word with 1+ digits on either side or complete word.

Answered By: anubhava

Can use the regexp (?:d|b){0}(?:d|b) to match the target word with either a word-boundary or a digit on either side of it.

import re

def findWholeWord(w):
    return re.compile(r'(?:d|b){0}(?:d|b)'.format(w), flags=re.I).search

for s in [
    'this is Thomas again',
    'this is,Thomas again',
    'this is,Thomas, again',
    'this is.Thomas, again',
    'this is ?Thomas again',
    'this is 9Thomas, again',
    'this is9Thomas again',
    'this is Thomas36 again',
    'this is -Thomas- again',
    'athomas is no match',
    'thomason no match']:
    print("match >" if findWholeWord('thomas')(s) else "*no match* >", s)


match > this is Thomas again
match > this is,Thomas again
match > this is,Thomas, again
match > this is.Thomas, again
match > this is ?Thomas again
match > this is 9Thomas, again
match > this is9Thomas again
match > this is Thomas36 again
match > this is -Thomas- again
*no match* > athomas is no match
*no match* > thomason no match

If you want to reuse the same target word against multiple inputs or in a loop then you can assign findWholeWord() call to a variable then call it.

matcher = findWholeWord('thomas')
print(matcher('this is Thomas again'))
print(matcher('this is,Thomas again'))
Answered By: CodeMonkey
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