OpenStack I18N

OpenStack I18N

官方文档：
https://docs.openstack.org/oslo.i18n/latest/user/usage.html
https://docs.openstack.org/oslo.i18n/latest/user/guidelines.html

使用前准备

准备 .mo 文件

1. 运行 Python 安装目录下的 Tools/i18n/pygettext.py，生成 .pot 文件模版
messages.pot:

# SOME DESCRIPTIVE TITLE.
# Copyright (C) YEAR ORGANIZATION
# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
#
msgid ""
msgstr ""
"Project-Id-Version: PACKAGE VERSION
"
"POT-Creation-Date: 2019-10-23 13:37+0800
"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE
"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>
"
"Language-Team: LANGUAGE <LL@li.org>
"
"MIME-Version: 1.0
"
"Content-Type: text/plain; charset=UTF-8
"
"Content-Transfer-Encoding: 8bit
"
"Generated-By: pygettext.py 1.5
"

2. 修改 .pot 文件：写入翻译，保存为 .po 文件 (注意：无论代码中使用单引号还是双引号，.po 文件中必须用双引号)

messages.po:

# SOME DESCRIPTIVE TITLE.
# Copyright (C) YEAR ORGANIZATION
# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
#
msgid ""
msgstr ""
"Project-Id-Version: PACKAGE VERSION
"
"POT-Creation-Date: 2019-10-23 13:37+0800
"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE
"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>
"
"Language-Team: LANGUAGE <LL@li.org>
"
"MIME-Version: 1.0
"
"Content-Type: text/plain; charset=UTF-8
"
"Content-Transfer-Encoding: 8bit
"
"Generated-By: pygettext.py 1.5
"


msgid "Hello world"
msgstr "你好，世界"

3. 运行 Python 安装目录下的 Tools/i18n/msgfmt.py，通过 .po 文件生成 .mo 文件
4. 将 .mo 文件放入文件夹 <localedir>/<language>/LC_MESSAGES/<domain>.mo (默认为: /usr/share/locale/zh_CN/LC_MESSAGES/)，文件名为程序名

在项目中使用

实例化对象

首先需要实例化一个 oslo_i18n.TranslatorFactory 对象
之后将 .primary 封装成 (_)
在报错的字符串前使用 _ 函数对字符串进行处理

import oslo_i18n as i18n


DOMAIN = 'my_app'
_translators = i18n.TranslatorFactory(domain='my_app')

# The primary translation function using the well-known name "_"
_ = _translators.primary

# The contextual translation function using the name "_C"
# requires oslo.i18n >=2.1.0
_C = _translators.contextual_form
 
# The plural translation function using the name "_P"
# requires oslo.i18n >=2.1.0
_P = _translators.plural_form

# Translators for log levels.
#
# The abbreviated names are meant to reflect the usual use of a short
# name like '_'. The "L" is for "log" and the other letter comes from
# the level.
_LI = _translators.log_info
_LW = _translators.log_warning
_LE = _translators.log_error
_LC = _translators.log_critical


def translate(value, user_locale):
    return i18n.translate(value, user_locale)


def get_available_languages():
    return i18n.get_available_languages(DOMAIN)

翻译

将需要翻译的字符串使用 _() 处理

LOG.error('There was an error.')
raise LocalExceptionClass(_('An error occurred.'))

方法

_()

在使用 _() 函数时需要注意的是：_() 是用来标记代码中的可翻译字符串，所以应该直接传入字符串，而不是变量名

_C()

_C() 是用来进行上下文翻译的

_P()

_P() 是用来进行负数翻译的

Log Translation

官方不再支持日志翻译，如果需要翻译使用 _ 即可
之前支持的
LOG.INFO: _LI()
LOG.WARNING: _LW()
LOG.ERROR: _LE()
LOG.CRITICAL: _LC()

linux 系统语言

I18N 模块会根据 Linux 系统语言的设定，去寻找相应的语言包

查看和设置 Linux 系统语言

通过 echo $LANG 进行查看
通过 export LANG=en_US.UTF-8 进行临时修改 (即时生效，重启失效)
通过修改配置文件 /etc/locale.conf 可以永久生效，需要 source /etc/locale.conf 使其立即生效