Flask-Babel 简介

安装 Flask-Babel

Flask-Babel 是 Flask 的翻译扩展工具。安装命令如下：

pip install flask-babel

from flask import Flask, render_template

app = Flask(__name__)

@app.route('/')
def hello():
    day = "Saturday"
    return render_template('index.html', day=day)

if __name__ == '__main__':
    app.debug = True
    app.run()

然后在 hello.py 的同一级目录下创建一个叫 templates 的文件夹，在其中写一个 index.html，内容如下：

<p>Hello, world!</p>
<p>It's {{ day }} today.</p>

from flask import Flask, render_template

from flaskext.babel import Babel, gettext as _

app = Flask(__name__)
app.config['BABEL_DEFAULT_LOCALE'] = 'zh_CN'
babel = Babel(app)

@app.route('/')
def hello():
    s = _("Saturday")
    return render_template('index.html', day=day)

if __name__ == '__main__':
    app.debug = True
    app.run()

然后修改模板：

<p>{{ _("Hello, world!") }}</p>
<p>{{ _("It's %(day)s today", day=day) }}</p> 

[python: **.py]
[jinja2: **/templates/**.html]
extensions=jinja2.ext.autoescape,jinja2.ext.with_

生成翻译模板

这样 babel 就知道要从哪些位置搜索要翻译的字符串了。然后我们用 pybabel 生成要翻译的 PO 模板文件，这个命令是 babel 这个工具包带来的，生成翻译模板命令如下：

$ pybabel extract -F babel.cfg -o messages.pot .

注意结尾的点“.”，这个点表示当前目录，目录是 pybabel 必须的参数，官方文档中缺少这个点，所以命令是无法执行成功的。messages.pot 就是我们生成的翻译模板文件，内容大致如下：

# Translations template for PROJECT.
# Copyright (C) 2011 ORGANIZATION
# This file is distributed under the same license as the PROJECT project.
# FIRST AUTHOR , 2011.
#
#, fuzzy
msgid ""
msgstr ""
"Project-Id-Version: PROJECT VERSION\n"
"Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
"POT-Creation-Date: 2011-07-26 15:39+0800\n"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
"Last-Translator: FULL NAME \n"
"Language-Team: LANGUAGE \n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=utf-8\n"
"Content-Transfer-Encoding: 8bit\n"
"Generated-By: Babel 0.9.6\n"</code>

#: hello.py:11
msgid "Saturday"
msgstr ""

#: templates/index.html:1
msgid "Hello, world!"
msgstr ""

#: templates/index.html:2
#, python-format
msgid "It's %(day)s today"
msgstr ""

$ pybabel init -i messages.pot -d translations -l zh_CN

这句命令会在 hello 文件夹中生成一个 translations 文件夹，要确保 flask 能找到翻译内容，translations文件夹要和 templates 文件夹在同一个目录中。接下来我们就可以进行翻译了，修改translations/zh_CN/LC_MESSAGES/messages.po 文件，将其中的内容翻译过来：

# Chinese (China) translations for PROJECT.
# Copyright (C) 2011 ORGANIZATION
# This file is distributed under the same license as the PROJECT project.
# FIRST AUTHOR , 2011.
#
msgid ""
msgstr ""
"Project-Id-Version: PROJECT VERSION\n"
"Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
"POT-Creation-Date: 2011-07-26 15:39+0800\n"
"PO-Revision-Date: 2011-07-26 09:07+0800\n"
"Last-Translator: FULL NAME \n"
"Language-Team: zh_CN \n"
"Plural-Forms: nplurals=1; plural=0\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=utf-8\n"
"Content-Transfer-Encoding: 8bit\n"
"Generated-By: Babel 0.9.6\n"</code>

#: hello.py:11
msgid "Saturday"
msgstr "星期六"

#: templates/index.html:1
msgid "Hello, world!"
msgstr "哈罗，世界！"

#: templates/index.html:2
#, fuzzy, python-format
msgid "It's %(day)s today"
msgstr "今天是%(tag)s"