python regex to match both english and telugu/devanagari words

Question

I need some help in getting words from a mix of language it contains english and telugu language, here is my code so far

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import re 
sentence="hello world యూనియన్ యూనియన్" 
sentence=sentence.decode('utf-8') 
for m in re.finditer(ur'(\w|\’\w|\'\w)+', sentence, re.UNICODE): 
    start, end = m.span() 
    word = m.group().encode('utf-8') 
    print start, end, word 

the result i'm expecting is

0 5 hello 
6 11 world 
11 17 యూనియన్ 
17 23 యూనియన్  

but the result i get is

0 5 hello 
6 11 world 
12 13 య 
14 15 న 
16 18 యన 
20 21 య 
22 23 న 
24 26 యన 

the code split every character of the langauge and give independent start and end lengths. is there any way that i can get the result in the above format as words instead of characters

Answer 1

The point is that \w does not match diacritic symbols.

You may either use PyPi regex library and include \p{M} into your pattern, or define the cmobining marks Unicode ranges the way it is done in XRegExp package for JavaScript:

import re 
combining_marks_bmp = u'\u0300-\u036F\u0483-\u0489\u0591-\u05BD\u05BF\u05C1\u05C2\u05C4\u05C5\u05C7\u0610-\u061A\u064B-\u065F\u0670\u06D6-\u06DC\u06DF-\u06E4\u06E7\u06E8\u06EA-\u06ED\u0711\u0730-\u074A\u07A6-\u07B0\u07EB-\u07F3\u0816-\u0819\u081B-\u0823\u0825-\u0827\u0829-\u082D\u0859-\u085B\u08E3-\u0903\u093A-\u093C\u093E-\u094F\u0951-\u0957\u0962\u0963\u0981-\u0983\u09BC\u09BE-\u09C4\u09C7\u09C8\u09CB-\u09CD\u09D7\u09E2\u09E3\u0A01-\u0A03\u0A3C\u0A3E-\u0A42\u0A47\u0A48\u0A4B-\u0A4D\u0A51\u0A70\u0A71\u0A75\u0A81-\u0A83\u0ABC\u0ABE-\u0AC5\u0AC7-\u0AC9\u0ACB-\u0ACD\u0AE2\u0AE3\u0B01-\u0B03\u0B3C\u0B3E-\u0B44\u0B47\u0B48\u0B4B-\u0B4D\u0B56\u0B57\u0B62\u0B63\u0B82\u0BBE-\u0BC2\u0BC6-\u0BC8\u0BCA-\u0BCD\u0BD7\u0C00-\u0C03\u0C3E-\u0C44\u0C46-\u0C48\u0C4A-\u0C4D\u0C55\u0C56\u0C62\u0C63\u0C81-\u0C83\u0CBC\u0CBE-\u0CC4\u0CC6-\u0CC8\u0CCA-\u0CCD\u0CD5\u0CD6\u0CE2\u0CE3\u0D01-\u0D03\u0D3E-\u0D44\u0D46-\u0D48\u0D4A-\u0D4D\u0D57\u0D62\u0D63\u0D82\u0D83\u0DCA\u0DCF-\u0DD4\u0DD6\u0DD8-\u0DDF\u0DF2\u0DF3\u0E31\u0E34-\u0E3A\u0E47-\u0E4E\u0EB1\u0EB4-\u0EB9\u0EBB\u0EBC\u0EC8-\u0ECD\u0F18\u0F19\u0F35\u0F37\u0F39\u0F3E\u0F3F\u0F71-\u0F84\u0F86\u0F87\u0F8D-\u0F97\u0F99-\u0FBC\u0FC6\u102B-\u103E\u1056-\u1059\u105E-\u1060\u1062-\u1064\u1067-\u106D\u1071-\u1074\u1082-\u108D\u108F\u109A-\u109D\u135D-\u135F\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17B4-\u17D3\u17DD\u180B-\u180D\u18A9\u1920-\u192B\u1930-\u193B\u1A17-\u1A1B\u1A55-\u1A5E\u1A60-\u1A7C\u1A7F\u1AB0-\u1ABE\u1B00-\u1B04\u1B34-\u1B44\u1B6B-\u1B73\u1B80-\u1B82\u1BA1-\u1BAD\u1BE6-\u1BF3\u1C24-\u1C37\u1CD0-\u1CD2\u1CD4-\u1CE8\u1CED\u1CF2-\u1CF4\u1CF8\u1CF9\u1DC0-\u1DF5\u1DFC-\u1DFF\u20D0-\u20F0\u2CEF-\u2CF1\u2D7F\u2DE0-\u2DFF\u302A-\u302F\u3099\u309A\uA66F-\uA672\uA674-\uA67D\uA69E\uA69F\uA6F0\uA6F1\uA802\uA806\uA80B\uA823-\uA827\uA880\uA881\uA8B4-\uA8C4\uA8E0-\uA8F1\uA926-\uA92D\uA947-\uA953\uA980-\uA983\uA9B3-\uA9C0\uA9E5\uAA29-\uAA36\uAA43\uAA4C\uAA4D\uAA7B-\uAA7D\uAAB0\uAAB2-\uAAB4\uAAB7\uAAB8\uAABE\uAABF\uAAC1\uAAEB-\uAAEF\uAAF5\uAAF6\uABE3-\uABEA\uABEC\uABED\uFB1E\uFE00-\uFE0F\uFE20-\uFE2F'
combining_marks_astral = u'\uD805[\uDCB0-\uDCC3\uDDAF-\uDDB5\uDDB8-\uDDC0\uDDDC\uDDDD\uDE30-\uDE40\uDEAB-\uDEB7\uDF1D-\uDF2B]|\uD834[\uDD65-\uDD69\uDD6D-\uDD72\uDD7B-\uDD82\uDD85-\uDD8B\uDDAA-\uDDAD\uDE42-\uDE44]|\uD804[\uDC00-\uDC02\uDC38-\uDC46\uDC7F-\uDC82\uDCB0-\uDCBA\uDD00-\uDD02\uDD27-\uDD34\uDD73\uDD80-\uDD82\uDDB3-\uDDC0\uDDCA-\uDDCC\uDE2C-\uDE37\uDEDF-\uDEEA\uDF00-\uDF03\uDF3C\uDF3E-\uDF44\uDF47\uDF48\uDF4B-\uDF4D\uDF57\uDF62\uDF63\uDF66-\uDF6C\uDF70-\uDF74]|\uD81B[\uDF51-\uDF7E\uDF8F-\uDF92]|\uD81A[\uDEF0-\uDEF4\uDF30-\uDF36]|\uD82F[\uDC9D\uDC9E]|\uD800[\uDDFD\uDEE0\uDF76-\uDF7A]|\uD836[\uDE00-\uDE36\uDE3B-\uDE6C\uDE75\uDE84\uDE9B-\uDE9F\uDEA1-\uDEAF]|\uD802[\uDE01-\uDE03\uDE05\uDE06\uDE0C-\uDE0F\uDE38-\uDE3A\uDE3F\uDEE5\uDEE6]|\uD83A[\uDCD0-\uDCD6]|\uDB40[\uDD00-\uDDEF]'
pat = ur'(\w|’\w|\'\w|[{}]|{})+'.format(combining_marks_bmp, combining_marks_astral)
sentence="hello world యూనియన్ యూనియన్" 
sentence=sentence.decode('utf-8') 
for m in re.finditer(pat, sentence, re.UNICODE): 
    start, end = m.span() 
    word = m.group().encode('utf-8') 
    print start, end, word 

See the Python demo

Answer 2

I strongly suggest you to avoid using regex on non UTF characters it may seriously go out of your control. Why don't you just build some custom method using string properties and methods?

Here what I would do:

sentence="hello world యూనియన్ యూనియన్" 
res = sentence.split();
last_index = 0;
for word in res:
    start = sentence.index(word, last_index ) 
    end = start + len(word)
    last_index = end
    print(start, end, word) 

You can take a look at the example running here.