[Python-Dev] re with Unicode broken?

Fri, 13 Jul 2001 16:27:37 +0200

This is not for the faint of heart.

My validating XML parser doesn't work anymore, even though I didn't
change a thing (except update Python from CVS).  I use re extensively
in this parser, and all my expressions use Unicode extensively.
If I replace the Unicode stuff by ASCII, the expression works.

The expression which now fails to match is:

entity = re.compile('<!ENTITY'+_S+'(?:%'+_S+'(?P<pname>'+_Name+')'+_S+
	'(?P<pvalue>'+_EntityVal+'|'+_ExternalId+')|(?P<ename>'+_Name+')'+_S+
	'(?P<value>'+_EntityVal+'|'+_ExternalId+'(?:'+_S+'NDATA'+_S+_Name+
	')?))'+_opS+'>')

and the string it fails on is

<!ENTITY % SMIL.prefix "" >

In order to actually use the above expression, you need some more
variable definitions.  To assemble this into a working program, first
copy and paste the bottom part, then the middle part, and finally the
top part.

The resulting pattern is huge: (len(entity.pattern) == 15193).

First the ones that don't use Unicode.

_Letter = _BaseChar + _Ideographic
_NameChar = '-' + _Letter + _Digit + '._:' + _CombiningChar + _Extender
_S = '[ \t\r\n]+'                       # white space
_opS = '[ \t\r\n]*'                     # optional white space
_Name = '['+_Letter+'_:]['+_NameChar+']*' # XML Name
ref = '&(?:(?P<name>'+_Name+')|#(?P<char>(?:[0-9]+|x[0-9a-fA-F]+)));'
_QStr = "(?:'[^']*'|\"[^\"]*\")"        # quoted XML string
_EntityVal = '"(?:[^"&%]|'+ref+'|%'+_Name+';)*"|' \
             "'(?:[^'&%]|"+ref+"|%"+_Name+";)*'"
_SystemLiteral = '(?P<syslit>'+_QStr+')'
_PublicLiteral = '(?P<publit>"[-\'()+,./:=?;!*#@$_%% \n\ra-zA-Z0-9]*"|' \
                            "'[-()+,./:=?;!*#@$_%% \n\ra-zA-Z0-9]*')"
_ExternalId = '(?:SYSTEM|PUBLIC'+_S+_PublicLiteral+')'+_S+_SystemLiteral

The ASCII versions of the Unicode strings are (if you use these
definitions the re matches):

_BaseChar = 'A-Za-z'
_Ideographic = ''
_Digit = '0-9'
_CombiningChar = ''
_Extender = ''

and the Unicode versions (the ones that I actually use and that now
fail):

# The character sets below are taken directly from the XML spec.
_BaseChar = u'\u0041-\u005A\u0061-\u007A\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u00FF' \
            u'\u0100-\u0131\u0134-\u013E\u0141-\u0148\u014A-\u017E' \
            u'\u0180-\u01C3\u01CD-\u01F0\u01F4-\u01F5\u01FA-\u0217' \
            u'\u0250-\u02A8\u02BB-\u02C1\u0386\u0388-\u038A\u038C' \
            u'\u038E-\u03A1\u03A3-\u03CE\u03D0-\u03D6\u03DA\u03DC\u03DE' \
            u'\u03E0\u03E2-\u03F3\u0401-\u040C\u040E-\u044F\u0451-\u045C' \
            u'\u045E-\u0481\u0490-\u04C4\u04C7-\u04C8\u04CB-\u04CC' \
            u'\u04D0-\u04EB\u04EE-\u04F5\u04F8-\u04F9\u0531-\u0556\u0559' \
            u'\u0561-\u0586\u05D0-\u05EA\u05F0-\u05F2\u0621-\u063A' \
            u'\u0641-\u064A\u0671-\u06B7\u06BA-\u06BE\u06C0-\u06CE' \
            u'\u06D0-\u06D3\u06D5\u06E5-\u06E6\u0905-\u0939\u093D' \
            u'\u0958-\u0961\u0985-\u098C\u098F-\u0990\u0993-\u09A8' \
            u'\u09AA-\u09B0\u09B2\u09B6-\u09B9\u09DC-\u09DD\u09DF-\u09E1' \
            u'\u09F0-\u09F1\u0A05-\u0A0A\u0A0F-\u0A10\u0A13-\u0A28' \
            u'\u0A2A-\u0A30\u0A32-\u0A33\u0A35-\u0A36\u0A38-\u0A39' \
            u'\u0A59-\u0A5C\u0A5E\u0A72-\u0A74\u0A85-\u0A8B\u0A8D' \
            u'\u0A8F-\u0A91\u0A93-\u0AA8\u0AAA-\u0AB0\u0AB2-\u0AB3' \
            u'\u0AB5-\u0AB9\u0ABD\u0AE0\u0B05-\u0B0C\u0B0F-\u0B10' \
            u'\u0B13-\u0B28\u0B2A-\u0B30\u0B32-\u0B33\u0B36-\u0B39\u0B3D' \
            u'\u0B5C-\u0B5D\u0B5F-\u0B61\u0B85-\u0B8A\u0B8E-\u0B90' \
            u'\u0B92-\u0B95\u0B99-\u0B9A\u0B9C\u0B9E-\u0B9F\u0BA3-\u0BA4' \
            u'\u0BA8-\u0BAA\u0BAE-\u0BB5\u0BB7-\u0BB9\u0C05-\u0C0C' \
            u'\u0C0E-\u0C10\u0C12-\u0C28\u0C2A-\u0C33\u0C35-\u0C39' \
            u'\u0C60-\u0C61\u0C85-\u0C8C\u0C8E-\u0C90\u0C92-\u0CA8' \
            u'\u0CAA-\u0CB3\u0CB5-\u0CB9\u0CDE\u0CE0-\u0CE1\u0D05-\u0D0C' \
            u'\u0D0E-\u0D10\u0D12-\u0D28\u0D2A-\u0D39\u0D60-\u0D61' \
            u'\u0E01-\u0E2E\u0E30\u0E32-\u0E33\u0E40-\u0E45\u0E81-\u0E82' \
            u'\u0E84\u0E87-\u0E88\u0E8A\u0E8D\u0E94-\u0E97\u0E99-\u0E9F' \
            u'\u0EA1-\u0EA3\u0EA5\u0EA7\u0EAA-\u0EAB\u0EAD-\u0EAE\u0EB0' \
            u'\u0EB2-\u0EB3\u0EBD\u0EC0-\u0EC4\u0F40-\u0F47\u0F49-\u0F69' \
            u'\u10A0-\u10C5\u10D0-\u10F6\u1100\u1102-\u1103\u1105-\u1107' \
            u'\u1109\u110B-\u110C\u110E-\u1112\u113C\u113E\u1140\u114C' \
            u'\u114E\u1150\u1154-\u1155\u1159\u115F-\u1161\u1163\u1165' \
            u'\u1167\u1169\u116D-\u116E\u1172-\u1173\u1175\u119E\u11A8' \
            u'\u11AB\u11AE-\u11AF\u11B7-\u11B8\u11BA\u11BC-\u11C2\u11EB' \
            u'\u11F0\u11F9\u1E00-\u1E9B\u1EA0-\u1EF9\u1F00-\u1F15' \
            u'\u1F18-\u1F1D\u1F20-\u1F45\u1F48-\u1F4D\u1F50-\u1F57\u1F59' \
            u'\u1F5B\u1F5D\u1F5F-\u1F7D\u1F80-\u1FB4\u1FB6-\u1FBC\u1FBE' \
            u'\u1FC2-\u1FC4\u1FC6-\u1FCC\u1FD0-\u1FD3\u1FD6-\u1FDB' \
            u'\u1FE0-\u1FEC\u1FF2-\u1FF4\u1FF6-\u1FFC\u2126\u212A-\u212B' \
            u'\u212E\u2180-\u2182\u3041-\u3094\u30A1-\u30FA\u3105-\u312C' \
            u'\uAC00-\uD7A3'
_Ideographic = u'\u4E00-\u9FA5\u3007\u3021-\u3029'
_CombiningChar = u'\u0300-\u0345\u0360-\u0361\u0483-\u0486\u0591-\u05A1\u05A3-\u05B9' \
                 u'\u05BB-\u05BD\u05BF\u05C1-\u05C2\u05C4\u064B-\u0652\u0670' \
                 u'\u06D6-\u06DC\u06DD-\u06DF\u06E0-\u06E4\u06E7-\u06E8' \
                 u'\u06EA-\u06ED\u0901-\u0903\u093C\u093E-\u094C\u094D' \
                 u'\u0951-\u0954\u0962-\u0963\u0981-\u0983\u09BC\u09BE\u09BF' \
                 u'\u09C0-\u09C4\u09C7-\u09C8\u09CB-\u09CD\u09D7\u09E2-\u09E3' \
                 u'\u0A02\u0A3C\u0A3E\u0A3F\u0A40-\u0A42\u0A47-\u0A48' \
                 u'\u0A4B-\u0A4D\u0A70-\u0A71\u0A81-\u0A83\u0ABC\u0ABE-\u0AC5' \
                 u'\u0AC7-\u0AC9\u0ACB-\u0ACD\u0B01-\u0B03\u0B3C\u0B3E-\u0B43' \
                 u'\u0B47-\u0B48\u0B4B-\u0B4D\u0B56-\u0B57\u0B82-\u0B83' \
                 u'\u0BBE-\u0BC2\u0BC6-\u0BC8\u0BCA-\u0BCD\u0BD7\u0C01-\u0C03' \
                 u'\u0C3E-\u0C44\u0C46-\u0C48\u0C4A-\u0C4D\u0C55-\u0C56' \
                 u'\u0C82-\u0C83\u0CBE-\u0CC4\u0CC6-\u0CC8\u0CCA-\u0CCD' \
                 u'\u0CD5-\u0CD6\u0D02-\u0D03\u0D3E-\u0D43\u0D46-\u0D48' \
                 u'\u0D4A-\u0D4D\u0D57\u0E31\u0E34-\u0E3A\u0E47-\u0E4E\u0EB1' \
                 u'\u0EB4-\u0EB9\u0EBB-\u0EBC\u0EC8-\u0ECD\u0F18-\u0F19\u0F35' \
                 u'\u0F37\u0F39\u0F3E\u0F3F\u0F71-\u0F84\u0F86-\u0F8B' \
                 u'\u0F90-\u0F95\u0F97\u0F99-\u0FAD\u0FB1-\u0FB7\u0FB9' \
                 u'\u20D0-\u20DC\u20E1\u302A-\u302F\u3099\u309A'
_Digit = u'\u0030-\u0039\u0660-\u0669\u06F0-\u06F9\u0966-\u096F\u09E6-\u09EF' \
         u'\u0A66-\u0A6F\u0AE6-\u0AEF\u0B66-\u0B6F\u0BE7-\u0BEF' \
         u'\u0C66-\u0C6F\u0CE6-\u0CEF\u0D66-\u0D6F\u0E50-\u0E59' \
         u'\u0ED0-\u0ED9\u0F20-\u0F29'
_Extender = u'\u00B7\u02D0\u02D1\u0387\u0640\u0E46\u0EC6\u3005\u3031-\u3035' \
            u'\u309D-\u309E\u30FC-\u30FE'

-- Sjoerd Mullender <sjoerd.mullender@oratrix.com>