add subliminal for subtitle download. #253

libs/babelfish/language.py

@@ -0,0 +1,185 @@
+# -*- 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