| """Internationalization and localization support. | |
| This module provides internationalization (I18N) and localization (L10N) | |
| support for your Python programs by providing an interface to the GNU gettext | |
| message catalog library. | |
| I18N refers to the operation by which a program is made aware of multiple | |
| languages. L10N refers to the adaptation of your program, once | |
| internationalized, to the local language and cultural habits. | |
| """ | |
| # This module represents the integration of work, contributions, feedback, and | |
| # suggestions from the following people: | |
| # | |
| # Martin von Loewis, who wrote the initial implementation of the underlying | |
| # C-based libintlmodule (later renamed _gettext), along with a skeletal | |
| # gettext.py implementation. | |
| # | |
| # Peter Funk, who wrote fintl.py, a fairly complete wrapper around intlmodule, | |
| # which also included a pure-Python implementation to read .mo files if | |
| # intlmodule wasn't available. | |
| # | |
| # James Henstridge, who also wrote a gettext.py module, which has some | |
| # interesting, but currently unsupported experimental features: the notion of | |
| # a Catalog class and instances, and the ability to add to a catalog file via | |
| # a Python API. | |
| # | |
| # Barry Warsaw integrated these modules, wrote the .install() API and code, | |
| # and conformed all C and Python code to Python's coding standards. | |
| # | |
| # Francois Pinard and Marc-Andre Lemburg also contributed valuably to this | |
| # module. | |
| # | |
| # J. David Ibanez implemented plural forms. Bruno Haible fixed some bugs. | |
| # | |
| # TODO: | |
| # - Lazy loading of .mo files. Currently the entire catalog is loaded into | |
| # memory, but that's probably bad for large translated programs. Instead, | |
| # the lexical sort of original strings in GNU .mo files should be exploited | |
| # to do binary searches and lazy initializations. Or you might want to use | |
| # the undocumented double-hash algorithm for .mo files with hash tables, but | |
| # you'll need to study the GNU gettext code to do this. | |
| # | |
| # - Support Solaris .mo file formats. Unfortunately, we've been unable to | |
| # find this format documented anywhere. | |
| import locale, copy, os, re, struct, sys | |
| from errno import ENOENT | |
| __all__ = ['NullTranslations', 'GNUTranslations', 'Catalog', | |
| 'find', 'translation', 'install', 'textdomain', 'bindtextdomain', | |
| 'dgettext', 'dngettext', 'gettext', 'ngettext', | |
| ] | |
| _default_localedir = os.path.join(sys.prefix, 'share', 'locale') | |
| def test(condition, true, false): | |
| """ | |
| Implements the C expression: | |
| condition ? true : false | |
| Required to correctly interpret plural forms. | |
| """ | |
| if condition: | |
| return true | |
| else: | |
| return false | |
| def c2py(plural): | |
| """Gets a C expression as used in PO files for plural forms and returns a | |
| Python lambda function that implements an equivalent expression. | |
| """ | |
| # Security check, allow only the "n" identifier | |
| try: | |
| from cStringIO import StringIO | |
| except ImportError: | |
| from StringIO import StringIO | |
| import token, tokenize | |
| tokens = tokenize.generate_tokens(StringIO(plural).readline) | |
| try: | |
| danger = [x for x in tokens if x[0] == token.NAME and x[1] != 'n'] | |
| except tokenize.TokenError: | |
| raise ValueError, \ | |
| 'plural forms expression error, maybe unbalanced parenthesis' | |
| else: | |
| if danger: | |
| raise ValueError, 'plural forms expression could be dangerous' | |
| # Replace some C operators by their Python equivalents | |
| plural = plural.replace('&&', ' and ') | |
| plural = plural.replace('||', ' or ') | |
| expr = re.compile(r'\!([^=])') | |
| plural = expr.sub(' not \\1', plural) | |
| # Regular expression and replacement function used to transform | |
| # "a?b:c" to "test(a,b,c)". | |
| expr = re.compile(r'(.*?)\?(.*?):(.*)') | |
| def repl(x): | |
| return "test(%s, %s, %s)" % (x.group(1), x.group(2), | |
| expr.sub(repl, x.group(3))) | |
| # Code to transform the plural expression, taking care of parentheses | |
| stack = [''] | |
| for c in plural: | |
| if c == '(': | |
| stack.append('') | |
| elif c == ')': | |
| if len(stack) == 1: | |
| # Actually, we never reach this code, because unbalanced | |
| # parentheses get caught in the security check at the | |
| # beginning. | |
| raise ValueError, 'unbalanced parenthesis in plural form' | |
| s = expr.sub(repl, stack.pop()) | |
| stack[-1] += '(%s)' % s | |
| else: | |
| stack[-1] += c | |
| plural = expr.sub(repl, stack.pop()) | |
| return eval('lambda n: int(%s)' % plural) | |
| def _expand_lang(locale): | |
| from locale import normalize | |
| locale = normalize(locale) | |
| COMPONENT_CODESET = 1 << 0 | |
| COMPONENT_TERRITORY = 1 << 1 | |
| COMPONENT_MODIFIER = 1 << 2 | |
| # split up the locale into its base components | |
| mask = 0 | |
| pos = locale.find('@') | |
| if pos >= 0: | |
| modifier = locale[pos:] | |
| locale = locale[:pos] | |
| mask |= COMPONENT_MODIFIER | |
| else: | |
| modifier = '' | |
| pos = locale.find('.') | |
| if pos >= 0: | |
| codeset = locale[pos:] | |
| locale = locale[:pos] | |
| mask |= COMPONENT_CODESET | |
| else: | |
| codeset = '' | |
| pos = locale.find('_') | |
| if pos >= 0: | |
| territory = locale[pos:] | |
| locale = locale[:pos] | |
| mask |= COMPONENT_TERRITORY | |
| else: | |
| territory = '' | |
| language = locale | |
| ret = [] | |
| for i in range(mask+1): | |
| if not (i & ~mask): # if all components for this combo exist ... | |
| val = language | |
| if i & COMPONENT_TERRITORY: val += territory | |
| if i & COMPONENT_CODESET: val += codeset | |
| if i & COMPONENT_MODIFIER: val += modifier | |
| ret.append(val) | |
| ret.reverse() | |
| return ret | |
| class NullTranslations: | |
| def __init__(self, fp=None): | |
| self._info = {} | |
| self._charset = None | |
| self._output_charset = None | |
| self._fallback = None | |
| if fp is not None: | |
| self._parse(fp) | |
| def _parse(self, fp): | |
| pass | |
| def add_fallback(self, fallback): | |
| if self._fallback: | |
| self._fallback.add_fallback(fallback) | |
| else: | |
| self._fallback = fallback | |
| def gettext(self, message): | |
| if self._fallback: | |
| return self._fallback.gettext(message) | |
| return message | |
| def lgettext(self, message): | |
| if self._fallback: | |
| return self._fallback.lgettext(message) | |
| return message | |
| def ngettext(self, msgid1, msgid2, n): | |
| if self._fallback: | |
| return self._fallback.ngettext(msgid1, msgid2, n) | |
| if n == 1: | |
| return msgid1 | |
| else: | |
| return msgid2 | |
| def lngettext(self, msgid1, msgid2, n): | |
| if self._fallback: | |
| return self._fallback.lngettext(msgid1, msgid2, n) | |
| if n == 1: | |
| return msgid1 | |
| else: | |
| return msgid2 | |
| def ugettext(self, message): | |
| if self._fallback: | |
| return self._fallback.ugettext(message) | |
| return unicode(message) | |
| def ungettext(self, msgid1, msgid2, n): | |
| if self._fallback: | |
| return self._fallback.ungettext(msgid1, msgid2, n) | |
| if n == 1: | |
| return unicode(msgid1) | |
| else: | |
| return unicode(msgid2) | |
| def info(self): | |
| return self._info | |
| def charset(self): | |
| return self._charset | |
| def output_charset(self): | |
| return self._output_charset | |
| def set_output_charset(self, charset): | |
| self._output_charset = charset | |
| def install(self, unicode=False, names=None): | |
| import __builtin__ | |
| __builtin__.__dict__['_'] = unicode and self.ugettext or self.gettext | |
| if hasattr(names, "__contains__"): | |
| if "gettext" in names: | |
| __builtin__.__dict__['gettext'] = __builtin__.__dict__['_'] | |
| if "ngettext" in names: | |
| __builtin__.__dict__['ngettext'] = (unicode and self.ungettext | |
| or self.ngettext) | |
| if "lgettext" in names: | |
| __builtin__.__dict__['lgettext'] = self.lgettext | |
| if "lngettext" in names: | |
| __builtin__.__dict__['lngettext'] = self.lngettext | |
| class GNUTranslations(NullTranslations): | |
| # Magic number of .mo files | |
| LE_MAGIC = 0x950412deL | |
| BE_MAGIC = 0xde120495L | |
| def _parse(self, fp): | |
| """Override this method to support alternative .mo formats.""" | |
| unpack = struct.unpack | |
| filename = getattr(fp, 'name', '') | |
| # Parse the .mo file header, which consists of 5 little endian 32 | |
| # bit words. | |
| self._catalog = catalog = {} | |
| self.plural = lambda n: int(n != 1) # germanic plural by default | |
| buf = fp.read() | |
| buflen = len(buf) | |
| # Are we big endian or little endian? | |
| magic = unpack('<I', buf[:4])[0] | |
| if magic == self.LE_MAGIC: | |
| version, msgcount, masteridx, transidx = unpack('<4I', buf[4:20]) | |
| ii = '<II' | |
| elif magic == self.BE_MAGIC: | |
| version, msgcount, masteridx, transidx = unpack('>4I', buf[4:20]) | |
| ii = '>II' | |
| else: | |
| raise IOError(0, 'Bad magic number', filename) | |
| # Now put all messages from the .mo file buffer into the catalog | |
| # dictionary. | |
| for i in xrange(0, msgcount): | |
| mlen, moff = unpack(ii, buf[masteridx:masteridx+8]) | |
| mend = moff + mlen | |
| tlen, toff = unpack(ii, buf[transidx:transidx+8]) | |
| tend = toff + tlen | |
| if mend < buflen and tend < buflen: | |
| msg = buf[moff:mend] | |
| tmsg = buf[toff:tend] | |
| else: | |
| raise IOError(0, 'File is corrupt', filename) | |
| # See if we're looking at GNU .mo conventions for metadata | |
| if mlen == 0: | |
| # Catalog description | |
| lastk = k = None | |
| for item in tmsg.splitlines(): | |
| item = item.strip() | |
| if not item: | |
| continue | |
| if ':' in item: | |
| k, v = item.split(':', 1) | |
| k = k.strip().lower() | |
| v = v.strip() | |
| self._info[k] = v | |
| lastk = k | |
| elif lastk: | |
| self._info[lastk] += '\n' + item | |
| if k == 'content-type': | |
| self._charset = v.split('charset=')[1] | |
| elif k == 'plural-forms': | |
| v = v.split(';') | |
| plural = v[1].split('plural=')[1] | |
| self.plural = c2py(plural) | |
| # Note: we unconditionally convert both msgids and msgstrs to | |
| # Unicode using the character encoding specified in the charset | |
| # parameter of the Content-Type header. The gettext documentation | |
| # strongly encourages msgids to be us-ascii, but some applications | |
| # require alternative encodings (e.g. Zope's ZCML and ZPT). For | |
| # traditional gettext applications, the msgid conversion will | |
| # cause no problems since us-ascii should always be a subset of | |
| # the charset encoding. We may want to fall back to 8-bit msgids | |
| # if the Unicode conversion fails. | |
| if '\x00' in msg: | |
| # Plural forms | |
| msgid1, msgid2 = msg.split('\x00') | |
| tmsg = tmsg.split('\x00') | |
| if self._charset: | |
| msgid1 = unicode(msgid1, self._charset) | |
| tmsg = [unicode(x, self._charset) for x in tmsg] | |
| for i in range(len(tmsg)): | |
| catalog[(msgid1, i)] = tmsg[i] | |
| else: | |
| if self._charset: | |
| msg = unicode(msg, self._charset) | |
| tmsg = unicode(tmsg, self._charset) | |
| catalog[msg] = tmsg | |
| # advance to next entry in the seek tables | |
| masteridx += 8 | |
| transidx += 8 | |
| def gettext(self, message): | |
| missing = object() | |
| tmsg = self._catalog.get(message, missing) | |
| if tmsg is missing: | |
| if self._fallback: | |
| return self._fallback.gettext(message) | |
| return message | |
| # Encode the Unicode tmsg back to an 8-bit string, if possible | |
| if self._output_charset: | |
| return tmsg.encode(self._output_charset) | |
| elif self._charset: | |
| return tmsg.encode(self._charset) | |
| return tmsg | |
| def lgettext(self, message): | |
| missing = object() | |
| tmsg = self._catalog.get(message, missing) | |
| if tmsg is missing: | |
| if self._fallback: | |
| return self._fallback.lgettext(message) | |
| return message | |
| if self._output_charset: | |
| return tmsg.encode(self._output_charset) | |
| return tmsg.encode(locale.getpreferredencoding()) | |
| def ngettext(self, msgid1, msgid2, n): | |
| try: | |
| tmsg = self._catalog[(msgid1, self.plural(n))] | |
| if self._output_charset: | |
| return tmsg.encode(self._output_charset) | |
| elif self._charset: | |
| return tmsg.encode(self._charset) | |
| return tmsg | |
| except KeyError: | |
| if self._fallback: | |
| return self._fallback.ngettext(msgid1, msgid2, n) | |
| if n == 1: | |
| return msgid1 | |
| else: | |
| return msgid2 | |
| def lngettext(self, msgid1, msgid2, n): | |
| try: | |
| tmsg = self._catalog[(msgid1, self.plural(n))] | |
| if self._output_charset: | |
| return tmsg.encode(self._output_charset) | |
| return tmsg.encode(locale.getpreferredencoding()) | |
| except KeyError: | |
| if self._fallback: | |
| return self._fallback.lngettext(msgid1, msgid2, n) | |
| if n == 1: | |
| return msgid1 | |
| else: | |
| return msgid2 | |
| def ugettext(self, message): | |
| missing = object() | |
| tmsg = self._catalog.get(message, missing) | |
| if tmsg is missing: | |
| if self._fallback: | |
| return self._fallback.ugettext(message) | |
| return unicode(message) | |
| return tmsg | |
| def ungettext(self, msgid1, msgid2, n): | |
| try: | |
| tmsg = self._catalog[(msgid1, self.plural(n))] | |
| except KeyError: | |
| if self._fallback: | |
| return self._fallback.ungettext(msgid1, msgid2, n) | |
| if n == 1: | |
| tmsg = unicode(msgid1) | |
| else: | |
| tmsg = unicode(msgid2) | |
| return tmsg | |
| # Locate a .mo file using the gettext strategy | |
| def find(domain, localedir=None, languages=None, all=0): | |
| # Get some reasonable defaults for arguments that were not supplied | |
| if localedir is None: | |
| localedir = _default_localedir | |
| if languages is None: | |
| languages = [] | |
| for envar in ('LANGUAGE', 'LC_ALL', 'LC_MESSAGES', 'LANG'): | |
| val = os.environ.get(envar) | |
| if val: | |
| languages = val.split(':') | |
| break | |
| if 'C' not in languages: | |
| languages.append('C') | |
| # now normalize and expand the languages | |
| nelangs = [] | |
| for lang in languages: | |
| for nelang in _expand_lang(lang): | |
| if nelang not in nelangs: | |
| nelangs.append(nelang) | |
| # select a language | |
| if all: | |
| result = [] | |
| else: | |
| result = None | |
| for lang in nelangs: | |
| if lang == 'C': | |
| break | |
| mofile = os.path.join(localedir, lang, 'LC_MESSAGES', '%s.mo' % domain) | |
| if os.path.exists(mofile): | |
| if all: | |
| result.append(mofile) | |
| else: | |
| return mofile | |
| return result | |
| # a mapping between absolute .mo file path and Translation object | |
| _translations = {} | |
| def translation(domain, localedir=None, languages=None, | |
| class_=None, fallback=False, codeset=None): | |
| if class_ is None: | |
| class_ = GNUTranslations | |
| mofiles = find(domain, localedir, languages, all=1) | |
| if not mofiles: | |
| if fallback: | |
| return NullTranslations() | |
| raise IOError(ENOENT, 'No translation file found for domain', domain) | |
| # Avoid opening, reading, and parsing the .mo file after it's been done | |
| # once. | |
| result = None | |
| for mofile in mofiles: | |
| key = (class_, os.path.abspath(mofile)) | |
| t = _translations.get(key) | |
| if t is None: | |
| with open(mofile, 'rb') as fp: | |
| t = _translations.setdefault(key, class_(fp)) | |
| # Copy the translation object to allow setting fallbacks and | |
| # output charset. All other instance data is shared with the | |
| # cached object. | |
| t = copy.copy(t) | |
| if codeset: | |
| t.set_output_charset(codeset) | |
| if result is None: | |
| result = t | |
| else: | |
| result.add_fallback(t) | |
| return result | |
| def install(domain, localedir=None, unicode=False, codeset=None, names=None): | |
| t = translation(domain, localedir, fallback=True, codeset=codeset) | |
| t.install(unicode, names) | |
| # a mapping b/w domains and locale directories | |
| _localedirs = {} | |
| # a mapping b/w domains and codesets | |
| _localecodesets = {} | |
| # current global domain, `messages' used for compatibility w/ GNU gettext | |
| _current_domain = 'messages' | |
| def textdomain(domain=None): | |
| global _current_domain | |
| if domain is not None: | |
| _current_domain = domain | |
| return _current_domain | |
| def bindtextdomain(domain, localedir=None): | |
| global _localedirs | |
| if localedir is not None: | |
| _localedirs[domain] = localedir | |
| return _localedirs.get(domain, _default_localedir) | |
| def bind_textdomain_codeset(domain, codeset=None): | |
| global _localecodesets | |
| if codeset is not None: | |
| _localecodesets[domain] = codeset | |
| return _localecodesets.get(domain) | |
| def dgettext(domain, message): | |
| try: | |
| t = translation(domain, _localedirs.get(domain, None), | |
| codeset=_localecodesets.get(domain)) | |
| except IOError: | |
| return message | |
| return t.gettext(message) | |
| def ldgettext(domain, message): | |
| try: | |
| t = translation(domain, _localedirs.get(domain, None), | |
| codeset=_localecodesets.get(domain)) | |
| except IOError: | |
| return message | |
| return t.lgettext(message) | |
| def dngettext(domain, msgid1, msgid2, n): | |
| try: | |
| t = translation(domain, _localedirs.get(domain, None), | |
| codeset=_localecodesets.get(domain)) | |
| except IOError: | |
| if n == 1: | |
| return msgid1 | |
| else: | |
| return msgid2 | |
| return t.ngettext(msgid1, msgid2, n) | |
| def ldngettext(domain, msgid1, msgid2, n): | |
| try: | |
| t = translation(domain, _localedirs.get(domain, None), | |
| codeset=_localecodesets.get(domain)) | |
| except IOError: | |
| if n == 1: | |
| return msgid1 | |
| else: | |
| return msgid2 | |
| return t.lngettext(msgid1, msgid2, n) | |
| def gettext(message): | |
| return dgettext(_current_domain, message) | |
| def lgettext(message): | |
| return ldgettext(_current_domain, message) | |
| def ngettext(msgid1, msgid2, n): | |
| return dngettext(_current_domain, msgid1, msgid2, n) | |
| def lngettext(msgid1, msgid2, n): | |
| return ldngettext(_current_domain, msgid1, msgid2, n) | |
| # dcgettext() has been deemed unnecessary and is not implemented. | |
| # James Henstridge's Catalog constructor from GNOME gettext. Documented usage | |
| # was: | |
| # | |
| # import gettext | |
| # cat = gettext.Catalog(PACKAGE, localedir=LOCALEDIR) | |
| # _ = cat.gettext | |
| # print _('Hello World') | |
| # The resulting catalog object currently don't support access through a | |
| # dictionary API, which was supported (but apparently unused) in GNOME | |
| # gettext. | |
| Catalog = translation |