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bazarr/libs/babelfish/language.py

186 lines
6.7 KiB

# -*- coding: utf-8 -*-
#
# Copyright (c) 2013 the BabelFish authors. All rights reserved.
# Use of this source code is governed by the 3-clause BSD license
# that can be found in the LICENSE file.
#
from __future__ import unicode_literals
from collections import namedtuple
from functools import partial
from pkg_resources import resource_stream # @UnresolvedImport
from .converters import ConverterManager
from .country import Country
from .exceptions import LanguageConvertError
from .script import Script
from . import basestr
LANGUAGES = set()
LANGUAGE_MATRIX = []
#: The namedtuple used in the :data:`LANGUAGE_MATRIX`
IsoLanguage = namedtuple('IsoLanguage', ['alpha3', 'alpha3b', 'alpha3t', 'alpha2', 'scope', 'type', 'name', 'comment'])
f = resource_stream('babelfish', 'data/iso-639-3.tab')
f.readline()
for l in f:
iso_language = IsoLanguage(*l.decode('utf-8').split('\t'))
LANGUAGES.add(iso_language.alpha3)
LANGUAGE_MATRIX.append(iso_language)
f.close()
class LanguageConverterManager(ConverterManager):
""":class:`~babelfish.converters.ConverterManager` for language converters"""
entry_point = 'babelfish.language_converters'
internal_converters = ['alpha2 = babelfish.converters.alpha2:Alpha2Converter',
'alpha3b = babelfish.converters.alpha3b:Alpha3BConverter',
'alpha3t = babelfish.converters.alpha3t:Alpha3TConverter',
'name = babelfish.converters.name:NameConverter',
'scope = babelfish.converters.scope:ScopeConverter',
'type = babelfish.converters.type:LanguageTypeConverter',
'opensubtitles = babelfish.converters.opensubtitles:OpenSubtitlesConverter']
language_converters = LanguageConverterManager()
class LanguageMeta(type):
"""The :class:`Language` metaclass
Dynamically redirect :meth:`Language.frommycode` to :meth:`Language.fromcode` with the ``mycode`` `converter`
"""
def __getattr__(cls, name):
if name.startswith('from'):
return partial(cls.fromcode, converter=name[4:])
return type.__getattribute__(cls, name)
class Language(LanguageMeta(str('LanguageBase'), (object,), {})):
"""A human language
A human language is composed of a language part following the ISO-639
standard and can be country-specific when a :class:`~babelfish.country.Country`
is specified.
The :class:`Language` is extensible with custom converters (see :ref:`custom_converters`)
:param string language: the language as a 3-letter ISO-639-3 code
:param country: the country (if any) as a 2-letter ISO-3166 code or :class:`~babelfish.country.Country` instance
:type country: string or :class:`~babelfish.country.Country` or None
:param script: the script (if any) as a 4-letter ISO-15924 code or :class:`~babelfish.script.Script` instance
:type script: string or :class:`~babelfish.script.Script` or None
:param unknown: the unknown language as a three-letters ISO-639-3 code to use as fallback
:type unknown: string or None
:raise: ValueError if the language could not be recognized and `unknown` is ``None``
"""
def __init__(self, language, country=None, script=None, unknown=None):
if unknown is not None and language not in LANGUAGES:
language = unknown
if language not in LANGUAGES:
raise ValueError('%r is not a valid language' % language)
self.alpha3 = language
self.country = None
if isinstance(country, Country):
self.country = country
elif country is None:
self.country = None
else:
self.country = Country(country)
self.script = None
if isinstance(script, Script):
self.script = script
elif script is None:
self.script = None
else:
self.script = Script(script)
@classmethod
def fromcode(cls, code, converter):
"""Create a :class:`Language` by its `code` using `converter` to
:meth:`~babelfish.converters.LanguageReverseConverter.reverse` it
:param string code: the code to reverse
:param string converter: name of the :class:`~babelfish.converters.LanguageReverseConverter` to use
:return: the corresponding :class:`Language` instance
:rtype: :class:`Language`
"""
return cls(*language_converters[converter].reverse(code))
@classmethod
def fromietf(cls, ietf):
"""Create a :class:`Language` by from an IETF language code
:param string ietf: the ietf code
:return: the corresponding :class:`Language` instance
:rtype: :class:`Language`
"""
subtags = ietf.split('-')
language_subtag = subtags.pop(0).lower()
if len(language_subtag) == 2:
language = cls.fromalpha2(language_subtag)
else:
language = cls(language_subtag)
while subtags:
subtag = subtags.pop(0)
if len(subtag) == 2:
language.country = Country(subtag.upper())
else:
language.script = Script(subtag.capitalize())
if language.script is not None:
if subtags:
raise ValueError('Wrong IETF format. Unmatched subtags: %r' % subtags)
break
return language
def __getstate__(self):
return self.alpha3, self.country, self.script
def __setstate__(self, state):
self.alpha3, self.country, self.script = state
def __getattr__(self, name):
alpha3 = self.alpha3
country = self.country.alpha2 if self.country is not None else None
script = self.script.code if self.script is not None else None
try:
return language_converters[name].convert(alpha3, country, script)
except KeyError:
raise AttributeError(name)
def __hash__(self):
return hash(str(self))
def __eq__(self, other):
if isinstance(other, basestr):
return str(self) == other
if not isinstance(other, Language):
return False
return (self.alpha3 == other.alpha3 and
self.country == other.country and
self.script == other.script)
def __ne__(self, other):
return not self == other
def __bool__(self):
return self.alpha3 != 'und'
__nonzero__ = __bool__
def __repr__(self):
return '<Language [%s]>' % self
def __str__(self):
try:
s = self.alpha2
except LanguageConvertError:
s = self.alpha3
if self.country is not None:
s += '-' + str(self.country)
if self.script is not None:
s += '-' + str(self.script)
return s