unicode categories -- regex

[koara]

Hello all -- my question regards special meta characters for the re
module. I saw in the re module documentation about the possibility to
abstract to any alphanumeric unicode character with '\w'. However,
there was no info on constructing patterns for other unicode
categories, such as purely alphabetical characters, or punctuation
symbols etc.

I found that this category information actually IS available in python
-- in the standard module unicodedata. For example,
unicodedata.category(u'.') gives 'Po' for 'Punctuation, other' etc.

So how do i include this information in regular pattern search? Any
ideas? Thanks.


I'm talking about python2.5 here.

 

[=?ISO-8859-1?Q?=22Martin_v=2E_L=F6wis=22?=]

So how do i include this information in regular pattern search? Any

ideas?

At the moment, you have to generate a character class for this yourself,
e.g.

py> chars = [unichr(i) for i in range(sys.maxunicode)]
py> chars = [c for c in chars if unicodedata.category(c)=='Po']
py> expr = u'[\\' + u'\\'.join(chars)+"]"
py> expr = re.compile(expr)
py> expr.match(u"#")
<_sre.SRE_Match object at 0xb7ce1d40>
py> expr.match(u"a")
py> expr.match(u"\u05be")
<_sre.SRE_Match object at 0xb7ce1d78>

Creating this expression is fairly expensive, however, once compiled,
it has a compact representation in memory, and matching it is
efficient.

Contributions to support categories directly in re are welcome. Look
at the relevant Unicode recommendation on how to do that.

HTH,
Martin

 

[koara]

At the moment, you have to generate a character class for this yourself,

e.g.
...

Thank you Martin, this is exactly what i wanted to know.