Python实现Web应用国际化i18n的示例详解

@lru_cache(maxsize=None)
def get_translator(locale: str):
    return gettext.translation(
        'messages',
        localedir=os.path.join(os.path.dirname(__file__), 'locales'),
        languages=[locale],
        fallback=True
    )

def get_locale_from_request(request: Request) -> str:
    locale = (
        request.query_params.get('lang') or 
        request.cookies.get('locale') or 
        request.headers.get('accept-language', 'en')[:2]
    )
    if locale not in SUPPORTED_LANGUAGES:
        locale = 'en'  # 默认使用英语
    return locale

def i18n_middleware(get_locale: Callable[[Request], str]):
    async def middleware(request: Request, call_next):
        locale = get_locale(request)
        translator = get_translator(locale)
        request.state.locale = locale
        request.state.gettext = translator.gettext
        request.state.supported_languages = SUPPORTED_LANGUAGES
        response = await call_next(request)
        return response
    return middleware

# 在Jinja2模板中
{{ _('welcome_message') }}

def some_function(request):
    # 使用请求中的翻译函数
    welcome_text = request.state.gettext('welcome_message')