Python regex matching Unicode properties

The regex module (an alternative to the standard re module) supports Unicode codepoint properties with the \p{} syntax.


Have you tried Ponyguruma, a Python binding to the Oniguruma regular expression engine? In that engine you can simply say \p{Armenian} to match Armenian characters. \p{Ll} or \p{Zs} work too.


You can painstakingly use unicodedata on each character:

import unicodedata

def strip_accents(x):
    return u''.join(c for c in unicodedata.normalize('NFD', x) if unicodedata.category(c) != 'Mn')

Speaking of homegrown solutions, some time ago I wrote a small program to do just that - convert a unicode category written as \p{...} into a range of values, extracted from the unicode specification (v.5.0.0). Only categories are supported (ex.: L, Zs), and is restricted to the BMP. I'm posting it here in case someone find it useful (although that Oniguruma really seems a better option).

Example usage:

>>> from unicode_hack import regex
>>> pattern = regex(r'^\\p{Lu}(\\p{L}|\\p{N}|_)*')
>>> print pattern.match(u'疂_1+2').group(0)
疂_1
>>>

Here's the source. There is also a JavaScript version, using the same data.


You're right that Unicode property classes are not supported by the Python regex parser.

If you wanted to do a nice hack, that would be generally useful, you could create a preprocessor that scans a string for such class tokens (\p{M} or whatever) and replaces them with the corresponding character sets, so that, for example, \p{M} would become [\u0300–\u036F\u1DC0–\u1DFF\u20D0–\u20FF\uFE20–\uFE2F], and \P{M} would become [^\u0300–\u036F\u1DC0–\u1DFF\u20D0–\u20FF\uFE20–\uFE2F].

People would thank you. :)