gettextutils.py 文件源码

def get_available_languages(domain):
    """Lists the available languages for the given translation domain.

    :param domain: the domain to get languages for
    """
    if domain in _AVAILABLE_LANGUAGES:
        return copy.copy(_AVAILABLE_LANGUAGES[domain])

    localedir = '%s_LOCALEDIR' % domain.upper()
    find = lambda x: gettext.find(domain,
                                  localedir=os.environ.get(localedir),
                                  languages=[x])

    # NOTE(mrodden): en_US should always be available (and first in case
    # order matters) since our in-line message strings are en_US
    language_list = ['en_US']
    # NOTE(luisg): Babel <1.0 used a function called list(), which was
    # renamed to locale_identifiers() in >=1.0, the requirements master list
    # requires >=0.9.6, uncapped, so defensively work with both. We can remove
    # this check when the master list updates to >=1.0, and update all projects
    list_identifiers = (getattr(localedata, 'list', None) or
                        getattr(localedata, 'locale_identifiers'))
    locale_identifiers = list_identifiers()
    for i in locale_identifiers:
        if find(i) is not None:
            language_list.append(i)
    _AVAILABLE_LANGUAGES[domain] = language_list
    return copy.copy(language_list)