Source code for django.utils.translation
"""
Internationalization support.
"""
from contextlib import ContextDecorator
from decimal import ROUND_UP, Decimal
from django.utils.autoreload import autoreload_started, file_changed
from django.utils.functional import lazy
from django.utils.regex_helper import _lazy_re_compile
__all__ = [
"activate",
"deactivate",
"override",
"deactivate_all",
"get_language",
"get_language_from_request",
"get_language_info",
"get_language_bidi",
"check_for_language",
"to_language",
"to_locale",
"templatize",
"gettext",
"gettext_lazy",
"gettext_noop",
"ngettext",
"ngettext_lazy",
"pgettext",
"pgettext_lazy",
"npgettext",
"npgettext_lazy",
]
class TranslatorCommentWarning(SyntaxWarning):
pass
# Here be dragons, so a short explanation of the logic won't hurt:
# We are trying to solve two problems: (1) access settings, in particular
# settings.USE_I18N, as late as possible, so that modules can be imported
# without having to first configure Django, and (2) if some other code creates
# a reference to one of these functions, don't break that reference when we
# replace the functions with their real counterparts (once we do access the
# settings).
class Trans:
"""
The purpose of this class is to store the actual translation function upon
receiving the first call to that function. After this is done, changes to
USE_I18N will have no effect to which function is served upon request. If
your tests rely on changing USE_I18N, you can delete all the functions
from _trans.__dict__.
Note that storing the function with setattr will have a noticeable
performance effect, as access to the function goes the normal path,
instead of using __getattr__.
"""
def __getattr__(self, real_name):
from django.conf import settings
if settings.USE_I18N:
from django.utils.translation import trans_real as trans
from django.utils.translation.reloader import (
translation_file_changed,
watch_for_translation_changes,
)
autoreload_started.connect(
watch_for_translation_changes, dispatch_uid="translation_file_changed"
)
file_changed.connect(
translation_file_changed, dispatch_uid="translation_file_changed"
)
else:
from django.utils.translation import trans_null as trans
setattr(self, real_name, getattr(trans, real_name))
return getattr(trans, real_name)
_trans = Trans()
# The Trans class is no more needed, so remove it from the namespace.
del Trans
[docs]def npgettext(context, singular, plural, number):
return _trans.npgettext(context, singular, plural, number)
gettext_lazy = lazy(gettext, str)
pgettext_lazy = lazy(pgettext, str)
def lazy_number(func, resultclass, number=None, **kwargs):
if isinstance(number, int):
kwargs["number"] = number
proxy = lazy(func, resultclass)(**kwargs)
else:
original_kwargs = kwargs.copy()
class NumberAwareString(resultclass):
def __bool__(self):
return bool(kwargs["singular"])
def _get_number_value(self, values):
try:
return values[number]
except KeyError:
raise KeyError(
"Your dictionary lacks key '%s'. Please provide "
"it, because it is required to determine whether "
"string is singular or plural." % number
)
def _translate(self, number_value):
kwargs["number"] = number_value
return func(**kwargs)
def format(self, *args, **kwargs):
number_value = (
self._get_number_value(kwargs) if kwargs and number else args[0]
)
return self._translate(number_value).format(*args, **kwargs)
def __mod__(self, rhs):
if isinstance(rhs, dict) and number:
number_value = self._get_number_value(rhs)
else:
number_value = rhs
translated = self._translate(number_value)
try:
translated %= rhs
except TypeError:
# String doesn't contain a placeholder for the number.
pass
return translated
proxy = lazy(lambda **kwargs: NumberAwareString(), NumberAwareString)(**kwargs)
proxy.__reduce__ = lambda: (
_lazy_number_unpickle,
(func, resultclass, number, original_kwargs),
)
return proxy
def _lazy_number_unpickle(func, resultclass, number, kwargs):
return lazy_number(func, resultclass, number=number, **kwargs)
[docs]def ngettext_lazy(singular, plural, number=None):
return lazy_number(ngettext, str, singular=singular, plural=plural, number=number)
[docs]def npgettext_lazy(context, singular, plural, number=None):
return lazy_number(
npgettext, str, context=context, singular=singular, plural=plural, number=number
)
[docs]class override(ContextDecorator):
def __init__(self, language, deactivate=False):
self.language = language
self.deactivate = deactivate
def __enter__(self):
self.old_language = get_language()
if self.language is not None:
activate(self.language)
else:
deactivate_all()
def __exit__(self, exc_type, exc_value, traceback):
if self.old_language is None:
deactivate_all()
elif self.deactivate:
deactivate()
else:
activate(self.old_language)
def to_language(locale):
"""Turn a locale name (en_US) into a language name (en-us)."""
p = locale.find("_")
if p >= 0:
return locale[:p].lower() + "-" + locale[p + 1 :].lower()
else:
return locale.lower()
[docs]def to_locale(language):
"""Turn a language name (en-us) into a locale name (en_US)."""
lang, _, country = language.lower().partition("-")
if not country:
return language[:3].lower() + language[3:]
# A language with > 2 characters after the dash only has its first
# character after the dash capitalized; e.g. sr-latn becomes sr_Latn.
# A language with 2 characters after the dash has both characters
# capitalized; e.g. en-us becomes en_US.
country, _, tail = country.partition("-")
country = country.title() if len(country) > 2 else country.upper()
if tail:
country += "-" + tail
return lang + "_" + country
[docs]def get_language_from_request(request, check_path=False):
return _trans.get_language_from_request(request, check_path)
def get_language_from_path(path):
return _trans.get_language_from_path(path)
[docs]def get_supported_language_variant(lang_code, *, strict=False):
return _trans.get_supported_language_variant(lang_code, strict)
[docs]def templatize(src, **kwargs):
from .template import templatize
return templatize(src, **kwargs)
[docs]def get_language_info(lang_code):
from django.conf.locale import LANG_INFO
try:
lang_info = LANG_INFO[lang_code]
if "fallback" in lang_info and "name" not in lang_info:
info = get_language_info(lang_info["fallback"][0])
else:
info = lang_info
except KeyError:
if "-" not in lang_code:
raise KeyError("Unknown language code %s." % lang_code)
generic_lang_code = lang_code.split("-")[0]
try:
info = LANG_INFO[generic_lang_code]
except KeyError:
raise KeyError(
"Unknown language code %s and %s." % (lang_code, generic_lang_code)
)
if info:
info["name_translated"] = gettext_lazy(info["name"])
return info
trim_whitespace_re = _lazy_re_compile(r"\s*\n\s*")
def trim_whitespace(s):
return trim_whitespace_re.sub(" ", s.strip())
def round_away_from_one(value):
return int(Decimal(value - 1).quantize(Decimal("0"), rounding=ROUND_UP)) + 1
