"""
babel.support
~~~~~~~~~~~~~
Several classes and functions that help with integrating and using Babel
in applications.
.. note: the code in this module is not used by Babel itself
:copyright: (c) 2013-2024 by the Babel Team.
:license: BSD, see LICENSE for more details.
"""
from __future__ import annotations
import decimal
import gettext
import locale
import os
from collections.abc import Iterator
from typing import TYPE_CHECKING, Any, Callable, Iterable
from babel.core import Locale
from babel.dates import format_date, format_datetime, format_time, format_timedelta
from babel.numbers import (
format_compact_currency,
format_compact_decimal,
format_currency,
format_decimal,
format_percent,
format_scientific,
)
if TYPE_CHECKING:
from typing_extensions import Literal
from babel.dates import _PredefinedTimeFormat
class LazyProxy:
"""Class for proxy objects that delegate to a specified function to evaluate
the actual object.
>>> def greeting(name='world'):
... return 'Hello, %s!' % name
>>> lazy_greeting = LazyProxy(greeting, name='Joe')
>>> print(lazy_greeting)
Hello, Joe!
>>> u' ' + lazy_greeting
u' Hello, Joe!'
>>> u'(%s)' % lazy_greeting
u'(Hello, Joe!)'
This can be used, for example, to implement lazy translation functions that
delay the actual translation until the string is actually used. The
rationale for such behavior is that the locale of the user may not always
be available. In web applications, you only know the locale when processing
a request.
The proxy implementation attempts to be as complete as possible, so that
the lazy objects should mostly work as expected, for example for sorting:
>>> greetings = [
... LazyProxy(greeting, 'world'),
... LazyProxy(greeting, 'Joe'),
... LazyProxy(greeting, 'universe'),
... ]
>>> greetings.sort()
>>> for greeting in greetings:
... print(greeting)
Hello, Joe!
Hello, universe!
Hello, world!
"""
__slots__ = ['_func', '_args', '_kwargs', '_value', '_is_cache_enabled', '_attribute_error']
if TYPE_CHECKING:
_func: Callable[..., Any]
_args: tuple[Any, ...]
_kwargs: dict[str, Any]
_is_cache_enabled: bool
_value: Any
_attribute_error: AttributeError | None
def __init__(self, func: Callable[..., Any], *args: Any, enable_cache: bool = True, **kwargs: Any) -> None:
# Avoid triggering our own __setattr__ implementation
object.__setattr__(self, '_func', func)
object.__setattr__(self, '_args', args)
object.__setattr__(self, '_kwargs', kwargs)
object.__setattr__(self, '_is_cache_enabled', enable_cache)
object.__setattr__(self, '_value', None)
object.__setattr__(self, '_attribute_error', None)
@property
def value(self) -> Any:
if self._value is None:
try:
value = self._func(*self._args, **self._kwargs)
except AttributeError as error:
object.__setattr__(self, '_attribute_error', error)
raise
if not self._is_cache_enabled:
return value
object.__setattr__(self, '_value', value)
return self._value
def __contains__(self, key: object) -> bool:
return key in self.value
def __bool__(self) -> bool:
return bool(self.value)
def __dir__(self) -> list[str]:
return dir(self.value)
def __iter__(self) -> Iterator[Any]:
return iter(self.value)
def __len__(self) -> int:
return len(self.value)
def __str__(self) -> str:
return str(self.value)
def __add__(self, other: object) -> Any:
return self.value + other
def __radd__(self, other: object) -> Any:
return other + self.value
def __mod__(self, other: object) -> Any:
return self.value % other
def __rmod__(self, other: object) -> Any:
return other % self.value
def __mul__(self, other: object) -> Any:
return self.value * other
def __rmul__(self, other: object) -> Any:
return other * self.value
def __call__(self, *args: Any, **kwargs: Any) -> Any:
return self.value(*args, **kwargs)
def __lt__(self, other: object) -> bool:
return self.value < other
def __le__(self, other: object) -> bool:
return self.value <= other
def __eq__(self, other: object) -> bool:
return self.value == other
def __ne__(self, other: object) -> bool:
return self.value != other
def __gt__(self, other: object) -> bool:
return self.value > other
def __ge__(self, other: object) -> bool:
return self.value >= other
def __delattr__(self, name: str) -> None:
delattr(self.value, name)
def __getattr__(self, name: str) -> Any:
if self._attribute_error is not None:
raise self._attribute_error
return getattr(self.value, name)
def __setattr__(self, name: str, value: Any) -> None:
setattr(self.value, name, value)
def __delitem__(self, key: Any) -> None:
del self.value[key]
def __getitem__(self, key: Any) -> Any:
return self.value[key]
def __setitem__(self, key: Any, value: Any) -> None:
self.value[key] = value
def __copy__(self) -> LazyProxy:
return LazyProxy(
self._func,
enable_cache=self._is_cache_enabled,
*self._args, # noqa: B026
**self._kwargs,
)
def __deepcopy__(self, memo: Any) -> LazyProxy:
from copy import deepcopy
return LazyProxy(
deepcopy(self._func, memo),
enable_cache=deepcopy(self._is_cache_enabled, memo),
*deepcopy(self._args, memo), # noqa: B026
**deepcopy(self._kwargs, memo),
)
class NullTranslations(gettext.NullTranslations):
if TYPE_CHECKING:
_info: dict[str, str]
_fallback: NullTranslations | None
DEFAULT_DOMAIN = None
def __init__(self, fp: gettext._TranslationsReader | None = None) -> None:
"""Initialize a simple translations class which is not backed by a
real catalog. Behaves similar to gettext.NullTranslations but also
offers Babel's on *gettext methods (e.g. 'dgettext()').
:param fp: a file-like object (ignored in this class)
"""
# These attributes are set by gettext.NullTranslations when a catalog
# is parsed (fp != None). Ensure that they are always present because
# some *gettext methods (including '.gettext()') rely on the attributes.
self._catalog: dict[tuple[str, Any] | str, str] = {}
self.plural: Callable[[float | decimal.Decimal], int] = lambda n: int(n != 1)
super().__init__(fp=fp)
self.files = list(filter(None, [getattr(fp, 'name', None)]))
self.domain = self.DEFAULT_DOMAIN
self._domains: dict[str, NullTranslations] = {}
def dgettext(self, domain: str, message: str) -> str:
"""Like ``gettext()``, but look the message up in the specified
domain.
"""
return self._domains.get(domain, self).gettext(message)
def ldgettext(self, domain: str, message: str) -> str:
"""Like ``lgettext()``, but look the message up in the specified
domain.
"""
import warnings
warnings.warn(
'ldgettext() is deprecated, use dgettext() instead',
DeprecationWarning,
stacklevel=2,
)
return self._domains.get(domain, self).lgettext(message)
def udgettext(self, domain: str, message: str) -> str:
"""Like ``ugettext()``, but look the message up in the specified
domain.
"""
return self._domains.get(domain, self).ugettext(message)
# backward compatibility with 0.9
dugettext = udgettext
def dngettext(self, domain: str, singular: str, plural: str, num: int) -> str:
"""Like ``ngettext()``, but look the message up in the specified
domain.
"""
return self._domains.get(domain, self).ngettext(singular, plural, num)
def ldngettext(self, domain: str, singular: str, plural: str, num: int) -> str:
"""Like ``lngettext()``, but look the message up in the specified
domain.
"""
import warnings
warnings.warn(
'ldngettext() is deprecated, use dngettext() instead',
DeprecationWarning,
stacklevel=2,
)
return self._domains.get(domain, self).lngettext(singular, plural, num)
def udngettext(self, domain: str, singular: str, plural: str, num: int) -> str:
"""Like ``ungettext()`` but look the message up in the specified
domain.
"""
return self._domains.get(domain, self).ungettext(singular, plural, num)
# backward compatibility with 0.9
dungettext = udngettext
# Most of the downwards code, until it gets included in stdlib, from:
# https://bugs.python.org/file10036/gettext-pgettext.patch
#
# The encoding of a msgctxt and a msgid in a .mo file is
# msgctxt + "\x04" + msgid (gettext version >= 0.15)
CONTEXT_ENCODING = '%s\x04%s'
def pgettext(self, context: str, message: str) -> str | object:
"""Look up the `context` and `message` id in the catalog and return the
corresponding message string, as an 8-bit string encoded with the
catalog's charset encoding, if known. If there is no entry in the
catalog for the `message` id and `context` , and a fallback has been
set, the look up is forwarded to the fallback's ``pgettext()``
method. Otherwise, the `message` id is returned.
"""
ctxt_msg_id = self.CONTEXT_ENCODING % (context, message)
missing = object()
tmsg = self._catalog.get(ctxt_msg_id, missing)
if tmsg is missing:
tmsg = self._catalog.get((ctxt_msg_id, self.plural(1)), missing)
if tmsg is not missing:
return tmsg
if self._fallback:
return self._fallback.pgettext(context, message)
return message
def lpgettext(self, context: str, message: str) -> str | bytes | object:
"""Equivalent to ``pgettext()``, but the translation is returned in the
preferred system encoding, if no other encoding was explicitly set with
``bind_textdomain_codeset()``.
"""
import warnings
warnings.warn(
'lpgettext() is deprecated, use pgettext() instead',
DeprecationWarning,
stacklevel=2,
)
tmsg = self.pgettext(context, message)
encoding = getattr(self, "_output_charset", None) or locale.getpreferredencoding()
return tmsg.encode(encoding) if isinstance(tmsg, str) else tmsg
def npgettext(self, context: str, singular: str, plural: str, num: int) -> str:
"""Do a plural-forms lookup of a message id. `singular` is used as the
message id for purposes of lookup in the catalog, while `num` is used to
determine which plural form to use. The returned message string is an
8-bit string encoded with the catalog's charset encoding, if known.
If the message id for `context` is not found in the catalog, and a
fallback is specified, the request is forwarded to the fallback's
``npgettext()`` method. Otherwise, when ``num`` is 1 ``singular`` is
returned, and ``plural`` is returned in all other cases.
"""
ctxt_msg_id = self.CONTEXT_ENCODING % (context, singular)
try:
tmsg = self._catalog[(ctxt_msg_id, self.plural(num))]
return tmsg
except KeyError:
if self._fallback:
return self._fallback.npgettext(context, singular, plural, num)
if num == 1:
return singular
else:
return plural
def lnpgettext(self, context: str, singular: str, plural: str, num: int) -> str | bytes:
"""Equivalent to ``npgettext()``, but the translation is returned in the
preferred system encoding, if no other encoding was explicitly set with
``bind_textdomain_codeset()``.
"""
import warnings
warnings.warn(
'lnpgettext() is deprecated, use npgettext() instead',
DeprecationWarning,
stacklevel=2,
)
ctxt_msg_id = self.CONTEXT_ENCODING % (context, singular)
try:
tmsg = self._catalog[(ctxt_msg_id, self.plural(num))]
encoding = getattr(self, "_output_charset", None) or locale.getpreferredencoding()
return tmsg.encode(encoding)
except KeyError:
if self._fallback:
return self._fallback.lnpgettext(context, singular, plural, num)
if num == 1:
return singular
else:
return plural
def upgettext(self, context: str, message: str) -> str:
"""Look up the `context` and `message` id in the catalog and return the
corresponding message string, as a Unicode string. If there is no entry
in the catalog for the `message` id and `context`, and a fallback has
been set, the look up is forwarded to the fallback's ``upgettext()``
method. Otherwise, the `message` id is returned.
"""
ctxt_message_id = self.CONTEXT_ENCODING % (context, message)
missing = object()
tmsg = self._catalog.get(ctxt_message_id, missing)
if tmsg is missing:
if self._fallback:
return self._fallback.upgettext(context, message)
return str(message)
assert isinstance(tmsg, str)
return tmsg
def unpgettext(self, context: str, singular: str, plural: str, num: int) -> str:
"""Do a plural-forms lookup of a message id. `singular` is used as the
message id for purposes of lookup in the catalog, while `num` is used to
determine which plural form to use. The returned message string is a
Unicode string.
If the message id for `context` is not found in the catalog, and a
fallback is specified, the request is forwarded to the fallback's
``unpgettext()`` method. Otherwise, when `num` is 1 `singular` is
returned, and `plural` is returned in all other cases.
"""
ctxt_message_id = self.CONTEXT_ENCODING % (context, singular)
try:
tmsg = self._catalog[(ctxt_message_id, self.plural(num))]
except KeyError:
if self._fallback:
return self._fallback.unpgettext(context, singular, plural, num)
tmsg = str(singular) if num == 1 else str(plural)
return tmsg
def dpgettext(self, domain: str, context: str, message: str) -> str | object:
"""Like `pgettext()`, but look the message up in the specified
`domain`.
"""
return self._domains.get(domain, self).pgettext(context, message)
def udpgettext(self, domain: str, context: str, message: str) -> str:
"""Like `upgettext()`, but look the message up in the specified
`domain`.
"""
return self._domains.get(domain, self).upgettext(context, message)
# backward compatibility with 0.9
dupgettext = udpgettext
def ldpgettext(self, domain: str, context: str, message: str) -> str | bytes | object:
"""Equivalent to ``dpgettext()``, but the translation is returned in the
preferred system encoding, if no other encoding was explicitly set with
``bind_textdomain_codeset()``.
"""
return self._domains.get(domain, self).lpgettext(context, message)
def dnpgettext(self, domain: str, context: str, singular: str, plural: str, num: int) -> str:
"""Like ``npgettext``, but look the message up in the specified
`domain`.
"""
return self._domains.get(domain, self).npgettext(context, singular,
plural, num)
def udnpgettext(self, domain: str, context: str, singular: str, plural: str, num: int) -> str:
"""Like ``unpgettext``, but look the message up in the specified
`domain`.
"""
return self._domains.get(domain, self).unpgettext(context, singular,
plural, num)
# backward compatibility with 0.9
dunpgettext = udnpgettext
def ldnpgettext(self, domain: str, context: str, singular: str, plural: str, num: int) -> str | bytes:
"""Equivalent to ``dnpgettext()``, but the translation is returned in
the preferred system encoding, if no other encoding was explicitly set
with ``bind_textdomain_codeset()``.
"""
return self._domains.get(domain, self).lnpgettext(context, singular,
plural, num)
ugettext = gettext.NullTranslations.gettext
ungettext = gettext.NullTranslations.ngettext
class Translations(NullTranslations, gettext.GNUTranslations):
"""An extended translation catalog class."""
DEFAULT_DOMAIN = 'messages'
def __init__(self, fp: gettext._TranslationsReader | None = None, domain: str | None = None):
"""Initialize the translations catalog.
:param fp: the file-like object the translation should be read from
:param domain: the message domain (default: 'messages')
"""
super().__init__(fp=fp)
self.domain = domain or self.DEFAULT_DOMAIN
ugettext = gettext.GNUTranslations.gettext
ungettext = gettext.GNUTranslations.ngettext
@classmethod
def load(
cls,
dirname: str | os.PathLike[str] | None = None,
locales: Iterable[str | Locale] | str | Locale | None = None,
domain: str | None = None,
) -> NullTranslations:
"""Load translations from the given directory.
:param dirname: the directory containing the ``MO`` files
:param locales: the list of locales in order of preference (items in
this list can be either `Locale` objects or locale
strings)
:param domain: the message domain (default: 'messages')
"""
if not domain:
domain = cls.DEFAULT_DOMAIN
filename = gettext.find(domain, dirname, _locales_to_names(locales))
if not filename:
return NullTranslations()
with open(filename, 'rb') as fp:
return cls(fp=fp, domain=domain)
def __repr__(self) -> str:
version = self._info.get('project-id-version')
return f'<{type(self).__name__}: "{version}">'
def add(self, translations: Translations, merge: bool = True):
"""Add the given translations to the catalog.
If the domain of the translations is different than that of the
current catalog, they are added as a catalog that is only accessible
by the various ``d*gettext`` functions.
:param translations: the `Translations` instance with the messages to
add
:param merge: whether translations for message domains that have
already been added should be merged with the existing
translations
"""
domain = getattr(translations, 'domain', self.DEFAULT_DOMAIN)
if merge and domain == self.domain:
return self.merge(translations)
existing = self._domains.get(domain)
if merge and isinstance(existing, Translations):
existing.merge(translations)
else:
translations.add_fallback(self)
self._domains[domain] = translations
return self
def merge(self, translations: Translations):
"""Merge the given translations into the catalog.
Message translations in the specified catalog override any messages
with the same identifier in the existing catalog.
:param translations: the `Translations` instance with the messages to
merge
"""
if isinstance(translations, gettext.GNUTranslations):
self._catalog.update(translations._catalog)
if isinstance(translations, Translations):
self.files.extend(translations.files)
return self
def _locales_to_names(
locales: Iterable[str | Locale] | str | Locale | None,
) -> list[str] | None:
"""Normalize a `locales` argument to a list of locale names.
:param locales: the list of locales in order of preference (items in
this list can be either `Locale` objects or locale
strings)
"""
if locales is None:
return None
if isinstance(locales, Locale):
return [str(locales)]
if isinstance(locales, str):
return [locales]
return [str(locale) for locale in locales]
Shibuya