Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 1 | """Internationalization and localization support. |
| 2 | |
| 3 | This module provides internationalization (I18N) and localization (L10N) |
| 4 | support for your Python programs by providing an interface to the GNU gettext |
| 5 | message catalog library. |
| 6 | |
| 7 | I18N refers to the operation by which a program is made aware of multiple |
| 8 | languages. L10N refers to the adaptation of your program, once |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 9 | internationalized, to the local language and cultural habits. |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 10 | |
| 11 | """ |
| 12 | |
Barry Warsaw | fa488ec | 2000-08-25 20:26:43 +0000 | [diff] [blame] | 13 | # This module represents the integration of work, contributions, feedback, and |
| 14 | # suggestions from the following people: |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 15 | # |
| 16 | # Martin von Loewis, who wrote the initial implementation of the underlying |
| 17 | # C-based libintlmodule (later renamed _gettext), along with a skeletal |
| 18 | # gettext.py implementation. |
| 19 | # |
| 20 | # Peter Funk, who wrote fintl.py, a fairly complete wrapper around intlmodule, |
| 21 | # which also included a pure-Python implementation to read .mo files if |
| 22 | # intlmodule wasn't available. |
| 23 | # |
| 24 | # James Henstridge, who also wrote a gettext.py module, which has some |
| 25 | # interesting, but currently unsupported experimental features: the notion of |
| 26 | # a Catalog class and instances, and the ability to add to a catalog file via |
| 27 | # a Python API. |
| 28 | # |
| 29 | # Barry Warsaw integrated these modules, wrote the .install() API and code, |
| 30 | # and conformed all C and Python code to Python's coding standards. |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 31 | # |
| 32 | # Francois Pinard and Marc-Andre Lemburg also contributed valuably to this |
| 33 | # module. |
| 34 | # |
| 35 | # TODO: |
| 36 | # - Lazy loading of .mo files. Currently the entire catalog is loaded into |
| 37 | # memory, but that's probably bad for large translated programs. Instead, |
| 38 | # the lexical sort of original strings in GNU .mo files should be exploited |
| 39 | # to do binary searches and lazy initializations. Or you might want to use |
| 40 | # the undocumented double-hash algorithm for .mo files with hash tables, but |
| 41 | # you'll need to study the GNU gettext code to do this. |
| 42 | # |
| 43 | # - Support Solaris .mo file formats. Unfortunately, we've been unable to |
| 44 | # find this format documented anywhere. |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 45 | |
| 46 | import os |
| 47 | import sys |
| 48 | import struct |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 49 | from errno import ENOENT |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 50 | |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 51 | _default_localedir = os.path.join(sys.prefix, 'share', 'locale') |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 52 | |
| 53 | |
| 54 | |
Barry Warsaw | fa488ec | 2000-08-25 20:26:43 +0000 | [diff] [blame] | 55 | def _expand_lang(locale): |
| 56 | from locale import normalize |
| 57 | locale = normalize(locale) |
| 58 | COMPONENT_CODESET = 1 << 0 |
| 59 | COMPONENT_TERRITORY = 1 << 1 |
| 60 | COMPONENT_MODIFIER = 1 << 2 |
| 61 | # split up the locale into its base components |
| 62 | mask = 0 |
| 63 | pos = locale.find('@') |
| 64 | if pos >= 0: |
| 65 | modifier = locale[pos:] |
| 66 | locale = locale[:pos] |
| 67 | mask |= COMPONENT_MODIFIER |
| 68 | else: |
| 69 | modifier = '' |
| 70 | pos = locale.find('.') |
| 71 | if pos >= 0: |
| 72 | codeset = locale[pos:] |
| 73 | locale = locale[:pos] |
| 74 | mask |= COMPONENT_CODESET |
| 75 | else: |
| 76 | codeset = '' |
| 77 | pos = locale.find('_') |
| 78 | if pos >= 0: |
| 79 | territory = locale[pos:] |
| 80 | locale = locale[:pos] |
| 81 | mask |= COMPONENT_TERRITORY |
| 82 | else: |
| 83 | territory = '' |
| 84 | language = locale |
| 85 | ret = [] |
| 86 | for i in range(mask+1): |
| 87 | if not (i & ~mask): # if all components for this combo exist ... |
| 88 | val = language |
| 89 | if i & COMPONENT_TERRITORY: val += territory |
| 90 | if i & COMPONENT_CODESET: val += codeset |
| 91 | if i & COMPONENT_MODIFIER: val += modifier |
| 92 | ret.append(val) |
| 93 | ret.reverse() |
| 94 | return ret |
| 95 | |
| 96 | |
| 97 | |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 98 | class NullTranslations: |
| 99 | def __init__(self, fp=None): |
| 100 | self._info = {} |
| 101 | self._charset = None |
| 102 | if fp: |
| 103 | self._parse(fp) |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 104 | |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 105 | def _parse(self, fp): |
| 106 | pass |
| 107 | |
| 108 | def gettext(self, message): |
| 109 | return message |
| 110 | |
| 111 | def ugettext(self, message): |
| 112 | return unicode(message) |
| 113 | |
| 114 | def info(self): |
| 115 | return self._info |
| 116 | |
| 117 | def charset(self): |
| 118 | return self._charset |
| 119 | |
| 120 | def install(self, unicode=0): |
| 121 | import __builtin__ |
| 122 | __builtin__.__dict__['_'] = unicode and self.ugettext or self.gettext |
| 123 | |
| 124 | |
| 125 | class GNUTranslations(NullTranslations): |
| 126 | # Magic number of .mo files |
| 127 | LE_MAGIC = 0x950412de |
| 128 | BE_MAGIC = struct.unpack('>i', struct.pack('<i', LE_MAGIC))[0] |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 129 | |
| 130 | def _parse(self, fp): |
| 131 | """Override this method to support alternative .mo formats.""" |
| 132 | unpack = struct.unpack |
| 133 | filename = getattr(fp, 'name', '') |
| 134 | # Parse the .mo file header, which consists of 5 little endian 32 |
| 135 | # bit words. |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 136 | self._catalog = catalog = {} |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 137 | buf = fp.read() |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 138 | # Are we big endian or little endian? |
| 139 | magic = unpack('<i', buf[:4])[0] |
| 140 | if magic == self.LE_MAGIC: |
| 141 | version, msgcount, masteridx, transidx = unpack('<4i', buf[4:20]) |
| 142 | ii = '<ii' |
| 143 | elif magic == self.BE_MAGIC: |
| 144 | version, msgcount, masteridx, transidx = unpack('>4i', buf[4:20]) |
| 145 | ii = '>ii' |
| 146 | else: |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 147 | raise IOError(0, 'Bad magic number', filename) |
| 148 | # |
| 149 | # Now put all messages from the .mo file buffer into the catalog |
| 150 | # dictionary. |
| 151 | for i in xrange(0, msgcount): |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 152 | mlen, moff = unpack(ii, buf[masteridx:masteridx+8]) |
| 153 | mend = moff + mlen |
| 154 | tlen, toff = unpack(ii, buf[transidx:transidx+8]) |
| 155 | tend = toff + tlen |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 156 | if mend < len(buf) and tend < len(buf): |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 157 | tmsg = buf[toff:tend] |
| 158 | catalog[buf[moff:mend]] = tmsg |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 159 | else: |
| 160 | raise IOError(0, 'File is corrupt', filename) |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 161 | # See if we're looking at GNU .mo conventions for metadata |
| 162 | if mlen == 0 and tmsg.lower().startswith('project-id-version:'): |
| 163 | # Catalog description |
| 164 | for item in tmsg.split('\n'): |
| 165 | item = item.strip() |
| 166 | if not item: |
| 167 | continue |
| 168 | k, v = item.split(':', 1) |
| 169 | k = k.strip().lower() |
| 170 | v = v.strip() |
| 171 | self._info[k] = v |
| 172 | if k == 'content-type': |
| 173 | self._charset = v.split('charset=')[1] |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 174 | # advance to next entry in the seek tables |
Barry Warsaw | fa488ec | 2000-08-25 20:26:43 +0000 | [diff] [blame] | 175 | masteridx += 8 |
| 176 | transidx += 8 |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 177 | |
| 178 | def gettext(self, message): |
| 179 | return self._catalog.get(message, message) |
| 180 | |
| 181 | def ugettext(self, message): |
| 182 | tmsg = self._catalog.get(message, message) |
| 183 | return unicode(tmsg, self._charset) |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 184 | |
| 185 | |
| 186 | |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 187 | # Locate a .mo file using the gettext strategy |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 188 | def find(domain, localedir=None, languages=None): |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 189 | # Get some reasonable defaults for arguments that were not supplied |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 190 | if localedir is None: |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 191 | localedir = _default_localedir |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 192 | if languages is None: |
| 193 | languages = [] |
| 194 | for envar in ('LANGUAGE', 'LC_ALL', 'LC_MESSAGES', 'LANG'): |
| 195 | val = os.environ.get(envar) |
| 196 | if val: |
| 197 | languages = val.split(':') |
| 198 | break |
| 199 | if 'C' not in languages: |
| 200 | languages.append('C') |
Barry Warsaw | fa488ec | 2000-08-25 20:26:43 +0000 | [diff] [blame] | 201 | # now normalize and expand the languages |
| 202 | langdict = {} |
| 203 | for lang in languages: |
| 204 | for nelang in _expand_lang(lang): |
| 205 | langdict[nelang] = nelang |
| 206 | languages = langdict.keys() |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 207 | # select a language |
| 208 | for lang in languages: |
| 209 | if lang == 'C': |
| 210 | break |
Barry Warsaw | 84314b7 | 2000-08-25 19:53:17 +0000 | [diff] [blame] | 211 | mofile = os.path.join(localedir, lang, 'LC_MESSAGES', '%s.mo' % domain) |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 212 | if os.path.exists(mofile): |
| 213 | return mofile |
| 214 | return None |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 215 | |
| 216 | |
| 217 | |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 218 | # a mapping between absolute .mo file path and Translation object |
| 219 | _translations = {} |
| 220 | |
| 221 | def translation(domain, localedir=None, languages=None, class_=None): |
| 222 | if class_ is None: |
| 223 | class_ = GNUTranslations |
| 224 | mofile = find(domain, localedir, languages) |
| 225 | if mofile is None: |
| 226 | raise IOError(ENOENT, 'No translation file found for domain', domain) |
| 227 | key = os.path.abspath(mofile) |
| 228 | # TBD: do we need to worry about the file pointer getting collected? |
| 229 | t = _translations.setdefault(key, class_(open(mofile, 'rb'))) |
| 230 | return t |
| 231 | |
| 232 | |
| 233 | |
| 234 | def install(domain, localedir=None, unicode=0): |
| 235 | translation(domain, localedir).install(unicode) |
| 236 | |
| 237 | |
| 238 | |
| 239 | # a mapping b/w domains and locale directories |
| 240 | _localedirs = {} |
| 241 | # current global domain, `messages' used for compatibility w/ GNU gettext |
| 242 | _current_domain = 'messages' |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 243 | |
| 244 | |
| 245 | def textdomain(domain=None): |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 246 | global _current_domain |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 247 | if domain is not None: |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 248 | _current_domain = domain |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 249 | return _current_domain |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 250 | |
| 251 | |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 252 | def bindtextdomain(domain, localedir=None): |
| 253 | global _localedirs |
| 254 | if localedir is not None: |
| 255 | _localedirs[domain] = localedir |
| 256 | return _localedirs.get(domain, _default_localedir) |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 257 | |
| 258 | |
| 259 | def dgettext(domain, message): |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 260 | try: |
| 261 | t = translation(domain, _localedirs.get(domain, None)) |
| 262 | except IOError: |
| 263 | return message |
| 264 | return t.gettext(message) |
| 265 | |
| 266 | |
| 267 | def gettext(message): |
| 268 | return dgettext(_current_domain, message) |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 269 | |
| 270 | |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 271 | # dcgettext() has been deemed unnecessary and is not implemented. |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 272 | |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 273 | # James Henstridge's Catalog constructor from GNOME gettext. Documented usage |
| 274 | # was: |
| 275 | # |
| 276 | # import gettext |
| 277 | # cat = gettext.Catalog(PACKAGE, localedir=LOCALEDIR) |
| 278 | # _ = cat.gettext |
| 279 | # print _('Hello World') |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 280 | |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 281 | # The resulting catalog object currently don't support access through a |
| 282 | # dictionary API, which was supported (but apparently unused) in GNOME |
| 283 | # gettext. |
Barry Warsaw | 95be23d | 2000-08-25 19:13:37 +0000 | [diff] [blame] | 284 | |
Barry Warsaw | 33d8d70 | 2000-08-30 03:29:58 +0000 | [diff] [blame^] | 285 | Catalog = translation |