decoratedstr.py

   1 #!/usr/bin/env python
   2 # -*- encoding: utf-8 -*-
   3
   4 __all__ = ['remove_decoration', 'decorated_match']
   5
   6 # for range \u00c0 \u0179
   7 char_to_alternatives_lower={
   8     u'a': u'àáâãäåāăą',
   9     u'c': u'çćĉċč',
  10     u'd': u'ďđ',
  11     u'e': u'èéêëēĕėęě',
  12     u'g': u'ĝğġģ',
  13     u'h': u'ĥħ',
  14     u'i': u'ìíîïĩīĭįı',
  15     u'j': u'ĵ',
  16     u'k': u'ķ',
  17     u'l': u'ĺļľŀł',
  18     u'n': u'ñńņňŉŋ',
  19     u'o': u'òóôöøōŏő',
  20     u'r': u'ŕŗř',
  21     u's': u'śŝşš',
  22     u't': u'ţťŧ',
  23     u'u': u'ùúûüũūŭůűų',
  24     u'w': u'ŵ',
  25     u'y': u'ýÿŷ',
  26     u'z': u'źżž',
  27 }
  28
  29 # This chars lower() function doesn't work
  30 char_to_alternatives_upper={
  31     u'I': u'İ',
  32 }
  33 char_to_alternatives={} # idem, but with upper case too
  34 for char,alternatives in char_to_alternatives_lower.iteritems():
  35     char_to_alternatives[char] = alternatives
  36     char_to_alternatives[char.upper()] = alternatives.upper()
  37 for char,alternatives in char_to_alternatives_upper.iteritems():
  38     char_to_alternatives[char] = alternatives
  39
  40 alternative_to_char = {} # reverse
  41 for char,alternatives in char_to_alternatives_lower.iteritems():
  42     for alternative in alternatives:
  43         alternative_to_char[alternative] = char
  44         alternative_to_char[alternative.upper()] = char.upper()
  45 for char,alternatives in char_to_alternatives_upper.iteritems():
  46     for alternative in alternatives:
  47         alternative_to_char[alternative] = char
  48
  49 # ligatures (only two chars supported)
  50 ligatures_expansions_lower = {
  51     u'æ': u'ae',
  52     # u'ĳ': u'ij', buggy: see http://en.wikipedia.org/wiki/Typographic_ligature
  53     u'œ': u'oe',
  54 }
  55
  56 ligatures_expansions = {} # idem, but with upper case too
  57 for ligature, expansion in ligatures_expansions_lower.iteritems():
  58     ligatures_expansions[ligature] = expansion
  59     ligatures_expansions[ligature.upper()] = expansion[0].upper()+expansion[1:]
  60
  61 ligatures_contractions = {} # reverse
  62 for ligature, expansion in ligatures_expansions_lower.iteritems():
  63     ligatures_contractions[expansion] = ligature
  64     ligatures_contractions[expansion[0].upper()+expansion[1:]] =  ligature.upper()
  65
  66 def remove_decoration(txt):
  67     result = u''
  68     for l in txt:
  69         l = alternative_to_char.get(l, l)
  70         l = ligatures_expansions.get(l, l)
  71         result += l
  72     return result
  73
  74 def decorated_match_single_char(c, casesensitive=False):
  75     assert type(c)==unicode
  76     if not casesensitive:
  77         c = c.lower()
  78     result = c + char_to_alternatives.get(c, u'')
  79     if not casesensitive:
  80         u = result.upper()
  81         if result != u:
  82             result += u
  83     if len(result)>1:
  84         return u'['+result+u']'
  85     else:
  86         return result
  87
  88 def decorated_match(txt, casesensitive=False):
  89     assert type(txt)==unicode
  90     result = u''
  91     txt = remove_decoration(txt)
  92     if not casesensitive:
  93         txt = txt.lower()
  94     i = 0
  95     while i<len(txt):
  96         c1 = txt[i] # current character
  97         c12 = txt[i:i+2] # both current and next characters. Contains a single char on last iteration so that it never matches, that is OK
  98         ligature = ligatures_contractions.get(c12, None)
  99         if ligature:
 100             result += u'('+ligature
 101             if not casesensitive:
 102                 result += u'|'+ligature.upper()
 103             result += u'|'+decorated_match_single_char(c12[0], casesensitive) \
 104                           +decorated_match_single_char(c12[1], casesensitive) \
 105                    +u')'
 106             i+=1 # skip next character, we allready did both
 107         else:
 108             result += decorated_match_single_char(c1, casesensitive)
 109         i += 1
 110     return result
 111
 112
 113 if __name__ == '__main__':
 114     import sys
 115     if len(sys.argv)<2:
 116         print >> sys.stderr, u'Missing required parameter. Try "Œuf"'
 117         sys.exit(1)
 118     input = unicode(' '.join(sys.argv[1:]), 'utf-8')
 119     print "input:", input                            # Œuf
 120     print "undecorated:", remove_decoration(input)   # Oeuf
 121     print "regex:", decorated_match(input)           # (œ|Œ|[oòóôöøōŏőOÒÓÔÖØŌŎŐ][eèéêëēĕėęěEÈÉÊËĒĔĖĘĚ])[uùúûüũūŭůűųUÙÚÛÜŨŪŬŮŰŲ][fF]