mirror of
https://github.com/python/cpython.git
synced 2025-10-31 02:15:10 +00:00
634 lines
20 KiB
Python
634 lines
20 KiB
Python
"""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 os
|
|
import re
|
|
import sys
|
|
|
|
|
|
__all__ = ['NullTranslations', 'GNUTranslations', 'Catalog',
|
|
'bindtextdomain', 'find', 'translation', 'install',
|
|
'textdomain', 'dgettext', 'dngettext', 'gettext',
|
|
'ngettext', 'pgettext', 'dpgettext', 'npgettext',
|
|
'dnpgettext'
|
|
]
|
|
|
|
_default_localedir = os.path.join(sys.base_prefix, 'share', 'locale')
|
|
|
|
# Expression parsing for plural form selection.
|
|
#
|
|
# The gettext library supports a small subset of C syntax. The only
|
|
# incompatible difference is that integer literals starting with zero are
|
|
# decimal.
|
|
#
|
|
# https://www.gnu.org/software/gettext/manual/gettext.html#Plural-forms
|
|
# http://git.savannah.gnu.org/cgit/gettext.git/tree/gettext-runtime/intl/plural.y
|
|
|
|
_token_pattern = re.compile(r"""
|
|
(?P<WHITESPACES>[ \t]+) | # spaces and horizontal tabs
|
|
(?P<NUMBER>[0-9]+\b) | # decimal integer
|
|
(?P<NAME>n\b) | # only n is allowed
|
|
(?P<PARENTHESIS>[()]) |
|
|
(?P<OPERATOR>[-*/%+?:]|[><!]=?|==|&&|\|\|) | # !, *, /, %, +, -, <, >,
|
|
# <=, >=, ==, !=, &&, ||,
|
|
# ? :
|
|
# unary and bitwise ops
|
|
# not allowed
|
|
(?P<INVALID>\w+|.) # invalid token
|
|
""", re.VERBOSE|re.DOTALL)
|
|
|
|
|
|
def _tokenize(plural):
|
|
for mo in re.finditer(_token_pattern, plural):
|
|
kind = mo.lastgroup
|
|
if kind == 'WHITESPACES':
|
|
continue
|
|
value = mo.group(kind)
|
|
if kind == 'INVALID':
|
|
raise ValueError('invalid token in plural form: %s' % value)
|
|
yield value
|
|
yield ''
|
|
|
|
|
|
def _error(value):
|
|
if value:
|
|
return ValueError('unexpected token in plural form: %s' % value)
|
|
else:
|
|
return ValueError('unexpected end of plural form')
|
|
|
|
|
|
_binary_ops = (
|
|
('||',),
|
|
('&&',),
|
|
('==', '!='),
|
|
('<', '>', '<=', '>='),
|
|
('+', '-'),
|
|
('*', '/', '%'),
|
|
)
|
|
_binary_ops = {op: i for i, ops in enumerate(_binary_ops, 1) for op in ops}
|
|
_c2py_ops = {'||': 'or', '&&': 'and', '/': '//'}
|
|
|
|
|
|
def _parse(tokens, priority=-1):
|
|
result = ''
|
|
nexttok = next(tokens)
|
|
while nexttok == '!':
|
|
result += 'not '
|
|
nexttok = next(tokens)
|
|
|
|
if nexttok == '(':
|
|
sub, nexttok = _parse(tokens)
|
|
result = '%s(%s)' % (result, sub)
|
|
if nexttok != ')':
|
|
raise ValueError('unbalanced parenthesis in plural form')
|
|
elif nexttok == 'n':
|
|
result = '%s%s' % (result, nexttok)
|
|
else:
|
|
try:
|
|
value = int(nexttok, 10)
|
|
except ValueError:
|
|
raise _error(nexttok) from None
|
|
result = '%s%d' % (result, value)
|
|
nexttok = next(tokens)
|
|
|
|
j = 100
|
|
while nexttok in _binary_ops:
|
|
i = _binary_ops[nexttok]
|
|
if i < priority:
|
|
break
|
|
# Break chained comparisons
|
|
if i in (3, 4) and j in (3, 4): # '==', '!=', '<', '>', '<=', '>='
|
|
result = '(%s)' % result
|
|
# Replace some C operators by their Python equivalents
|
|
op = _c2py_ops.get(nexttok, nexttok)
|
|
right, nexttok = _parse(tokens, i + 1)
|
|
result = '%s %s %s' % (result, op, right)
|
|
j = i
|
|
if j == priority == 4: # '<', '>', '<=', '>='
|
|
result = '(%s)' % result
|
|
|
|
if nexttok == '?' and priority <= 0:
|
|
if_true, nexttok = _parse(tokens, 0)
|
|
if nexttok != ':':
|
|
raise _error(nexttok)
|
|
if_false, nexttok = _parse(tokens)
|
|
result = '%s if %s else %s' % (if_true, result, if_false)
|
|
if priority == 0:
|
|
result = '(%s)' % result
|
|
|
|
return result, nexttok
|
|
|
|
|
|
def _as_int(n):
|
|
try:
|
|
i = round(n)
|
|
except TypeError:
|
|
raise TypeError('Plural value must be an integer, got %s' %
|
|
(n.__class__.__name__,)) from None
|
|
import warnings
|
|
warnings.warn('Plural value must be an integer, got %s' %
|
|
(n.__class__.__name__,),
|
|
DeprecationWarning, 4)
|
|
return n
|
|
|
|
|
|
def c2py(plural):
|
|
"""Gets a C expression as used in PO files for plural forms and returns a
|
|
Python function that implements an equivalent expression.
|
|
"""
|
|
|
|
if len(plural) > 1000:
|
|
raise ValueError('plural form expression is too long')
|
|
try:
|
|
result, nexttok = _parse(_tokenize(plural))
|
|
if nexttok:
|
|
raise _error(nexttok)
|
|
|
|
depth = 0
|
|
for c in result:
|
|
if c == '(':
|
|
depth += 1
|
|
if depth > 20:
|
|
# Python compiler limit is about 90.
|
|
# The most complex example has 2.
|
|
raise ValueError('plural form expression is too complex')
|
|
elif c == ')':
|
|
depth -= 1
|
|
|
|
ns = {'_as_int': _as_int}
|
|
exec('''if True:
|
|
def func(n):
|
|
if not isinstance(n, int):
|
|
n = _as_int(n)
|
|
return int(%s)
|
|
''' % result, ns)
|
|
return ns['func']
|
|
except RecursionError:
|
|
# Recursion error can be raised in _parse() or exec().
|
|
raise ValueError('plural form expression is too complex')
|
|
|
|
|
|
def _expand_lang(loc):
|
|
import locale
|
|
loc = locale.normalize(loc)
|
|
COMPONENT_CODESET = 1 << 0
|
|
COMPONENT_TERRITORY = 1 << 1
|
|
COMPONENT_MODIFIER = 1 << 2
|
|
# split up the locale into its base components
|
|
mask = 0
|
|
pos = loc.find('@')
|
|
if pos >= 0:
|
|
modifier = loc[pos:]
|
|
loc = loc[:pos]
|
|
mask |= COMPONENT_MODIFIER
|
|
else:
|
|
modifier = ''
|
|
pos = loc.find('.')
|
|
if pos >= 0:
|
|
codeset = loc[pos:]
|
|
loc = loc[:pos]
|
|
mask |= COMPONENT_CODESET
|
|
else:
|
|
codeset = ''
|
|
pos = loc.find('_')
|
|
if pos >= 0:
|
|
territory = loc[pos:]
|
|
loc = loc[:pos]
|
|
mask |= COMPONENT_TERRITORY
|
|
else:
|
|
territory = ''
|
|
language = loc
|
|
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._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 ngettext(self, msgid1, msgid2, n):
|
|
if self._fallback:
|
|
return self._fallback.ngettext(msgid1, msgid2, n)
|
|
if n == 1:
|
|
return msgid1
|
|
else:
|
|
return msgid2
|
|
|
|
def pgettext(self, context, message):
|
|
if self._fallback:
|
|
return self._fallback.pgettext(context, message)
|
|
return message
|
|
|
|
def npgettext(self, context, msgid1, msgid2, n):
|
|
if self._fallback:
|
|
return self._fallback.npgettext(context, msgid1, msgid2, n)
|
|
if n == 1:
|
|
return msgid1
|
|
else:
|
|
return msgid2
|
|
|
|
def info(self):
|
|
return self._info
|
|
|
|
def charset(self):
|
|
return self._charset
|
|
|
|
def install(self, names=None):
|
|
import builtins
|
|
builtins.__dict__['_'] = self.gettext
|
|
if names is not None:
|
|
allowed = {'gettext', 'ngettext', 'npgettext', 'pgettext'}
|
|
for name in allowed & set(names):
|
|
builtins.__dict__[name] = getattr(self, name)
|
|
|
|
|
|
class GNUTranslations(NullTranslations):
|
|
# Magic number of .mo files
|
|
LE_MAGIC = 0x950412de
|
|
BE_MAGIC = 0xde120495
|
|
|
|
# The encoding of a msgctxt and a msgid in a .mo file is
|
|
# msgctxt + "\x04" + msgid (gettext version >= 0.15)
|
|
CONTEXT = "%s\x04%s"
|
|
|
|
# Acceptable .mo versions
|
|
VERSIONS = (0, 1)
|
|
|
|
def _get_versions(self, version):
|
|
"""Returns a tuple of major version, minor version"""
|
|
return (version >> 16, version & 0xffff)
|
|
|
|
def _parse(self, fp):
|
|
"""Override this method to support alternative .mo formats."""
|
|
# Delay struct import for speeding up gettext import when .mo files
|
|
# are not used.
|
|
from struct import 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 OSError(0, 'Bad magic number', filename)
|
|
|
|
major_version, minor_version = self._get_versions(version)
|
|
|
|
if major_version not in self.VERSIONS:
|
|
raise OSError(0, 'Bad version number ' + str(major_version), filename)
|
|
|
|
# Now put all messages from the .mo file buffer into the catalog
|
|
# dictionary.
|
|
for i in range(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 OSError(0, 'File is corrupt', filename)
|
|
# See if we're looking at GNU .mo conventions for metadata
|
|
if mlen == 0:
|
|
# Catalog description
|
|
lastk = None
|
|
for b_item in tmsg.split(b'\n'):
|
|
item = b_item.decode().strip()
|
|
if not item:
|
|
continue
|
|
# Skip over comment lines:
|
|
if item.startswith('#-#-#-#-#') and item.endswith('#-#-#-#-#'):
|
|
continue
|
|
k = v = None
|
|
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.
|
|
charset = self._charset or 'ascii'
|
|
if b'\x00' in msg:
|
|
# Plural forms
|
|
msgid1, msgid2 = msg.split(b'\x00')
|
|
tmsg = tmsg.split(b'\x00')
|
|
msgid1 = str(msgid1, charset)
|
|
for i, x in enumerate(tmsg):
|
|
catalog[(msgid1, i)] = str(x, charset)
|
|
else:
|
|
catalog[str(msg, charset)] = str(tmsg, charset)
|
|
# 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
|
|
return tmsg
|
|
|
|
def ngettext(self, msgid1, msgid2, n):
|
|
try:
|
|
tmsg = self._catalog[(msgid1, self.plural(n))]
|
|
except KeyError:
|
|
if self._fallback:
|
|
return self._fallback.ngettext(msgid1, msgid2, n)
|
|
if n == 1:
|
|
tmsg = msgid1
|
|
else:
|
|
tmsg = msgid2
|
|
return tmsg
|
|
|
|
def pgettext(self, context, message):
|
|
ctxt_msg_id = self.CONTEXT % (context, message)
|
|
missing = object()
|
|
tmsg = self._catalog.get(ctxt_msg_id, missing)
|
|
if tmsg is missing:
|
|
if self._fallback:
|
|
return self._fallback.pgettext(context, message)
|
|
return message
|
|
return tmsg
|
|
|
|
def npgettext(self, context, msgid1, msgid2, n):
|
|
ctxt_msg_id = self.CONTEXT % (context, msgid1)
|
|
try:
|
|
tmsg = self._catalog[ctxt_msg_id, self.plural(n)]
|
|
except KeyError:
|
|
if self._fallback:
|
|
return self._fallback.npgettext(context, msgid1, msgid2, n)
|
|
if n == 1:
|
|
tmsg = msgid1
|
|
else:
|
|
tmsg = msgid2
|
|
return tmsg
|
|
|
|
|
|
# Locate a .mo file using the gettext strategy
|
|
def find(domain, localedir=None, languages=None, all=False):
|
|
# 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):
|
|
if class_ is None:
|
|
class_ = GNUTranslations
|
|
mofiles = find(domain, localedir, languages, all=True)
|
|
if not mofiles:
|
|
if fallback:
|
|
return NullTranslations()
|
|
from errno import ENOENT
|
|
raise FileNotFoundError(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.
|
|
# Delay copy import for speeding up gettext import when .mo files
|
|
# are not used.
|
|
import copy
|
|
t = copy.copy(t)
|
|
if result is None:
|
|
result = t
|
|
else:
|
|
result.add_fallback(t)
|
|
return result
|
|
|
|
|
|
def install(domain, localedir=None, *, names=None):
|
|
t = translation(domain, localedir, fallback=True)
|
|
t.install(names)
|
|
|
|
|
|
# a mapping b/w domains and locale directories
|
|
_localedirs = {}
|
|
# 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 dgettext(domain, message):
|
|
try:
|
|
t = translation(domain, _localedirs.get(domain, None))
|
|
except OSError:
|
|
return message
|
|
return t.gettext(message)
|
|
|
|
|
|
def dngettext(domain, msgid1, msgid2, n):
|
|
try:
|
|
t = translation(domain, _localedirs.get(domain, None))
|
|
except OSError:
|
|
if n == 1:
|
|
return msgid1
|
|
else:
|
|
return msgid2
|
|
return t.ngettext(msgid1, msgid2, n)
|
|
|
|
|
|
def dpgettext(domain, context, message):
|
|
try:
|
|
t = translation(domain, _localedirs.get(domain, None))
|
|
except OSError:
|
|
return message
|
|
return t.pgettext(context, message)
|
|
|
|
|
|
def dnpgettext(domain, context, msgid1, msgid2, n):
|
|
try:
|
|
t = translation(domain, _localedirs.get(domain, None))
|
|
except OSError:
|
|
if n == 1:
|
|
return msgid1
|
|
else:
|
|
return msgid2
|
|
return t.npgettext(context, msgid1, msgid2, n)
|
|
|
|
|
|
def gettext(message):
|
|
return dgettext(_current_domain, message)
|
|
|
|
|
|
def ngettext(msgid1, msgid2, n):
|
|
return dngettext(_current_domain, msgid1, msgid2, n)
|
|
|
|
|
|
def pgettext(context, message):
|
|
return dpgettext(_current_domain, context, message)
|
|
|
|
|
|
def npgettext(context, msgid1, msgid2, n):
|
|
return dnpgettext(_current_domain, context, 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
|