FastAPI BABEL

Get pybabbel tools directly within your FastAPI project without hassle.

FastAPI Babel is integrated within FastAPI framework and gives you support of i18n, l10n, date and time locales, and all other pybabel functionalities.

Features:

• I18n (Internationalization)
• Wtform Translation (Lazy Text)
• l10n (Localization)
• Date and time locale
• Decimal, Number locale
• Money and currency locale converter
• locale selector from HTTP header

Support

Python: 3.6 and later (tested on Python 3.6, 3.12) FastAPI: 0.45.0 + PyBabel: All

Installation

pip install fastapi-babel

How to use

1. install FastAPI and FastAPI Babel:

pip install fastapi

and

pip install fastapi_babel

2. make babel.py file:

from fastapi_babel import Babel, BabelConfigs

configs = BabelConfigs(
    ROOT_DIR=__file__,
    BABEL_DEFAULT_LOCALE="en",
    BABEL_TRANSLATION_DIRECTORY="lang",
)
babel = Babel(configs=configs)

if __name__ == "__main__":
    babel.run_cli()

3. make babel.cfg file

babel.cfg

[python: **.py]

4. Create main.py file:

from fastapi_babel import Babel, BabelConfigs, _

configs = BabelConfigs(
    ROOT_DIR=__file__,
    BABEL_DEFAULT_LOCALE="en",
    BABEL_TRANSLATION_DIRECTORY="lang",
)
babel = Babel(configs=configs)

def main():
    babel.locale = "en"
    en_text = _("Hello World")
    print(en_text)

    babel.locale = "fa"
    fa_text = _("Hello World")
    print(fa_text)

if __name__ == "__main__":
    main()

5. Extract the message

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

6. Initialize pybabel

pybabel init -i messages.pot -d lang -l fa

7. Goto lang/YOUR_LANGUAGE_CODE/LC_MESSAGES/messages.po and add your translation to your messages.

8. Go back to the root folder and Compile

pybabel compile -d lang

9. Run main.py

python3 main.py

• FastAPI Babel Commands

Install click at first: pip install click

1. Add this snippet to your FasAPI code:

...
babel.run_cli()
...

2. Now just follow the documentation from step 5.

For more information just take a look at help flag of main.py python main.py --help

Why FastAPI Babel CLI is recommanded ?

FastAPI Babel CLI will eliminate the need of concering the directories and paths, so you can concentrate on the project and spend less time on going forward and backward. You only need to specify domain name, babel.cfg and localization directory.

NOTICE: Do not use FastAPI Babel beside fastapi runner files (main.py or run.py), as uvicorn cli will not work.

[========]

Using FastAPI Babel in an API

• create file babel.py and write the code below.

from fastapi_babel import Babel, BabelConfigs, BabelMiddleware 

configs = BabelConfigs(
    ROOT_DIR=__file__,
    BABEL_DEFAULT_LOCALE="en",
    BABEL_TRANSLATION_DIRECTORY="lang",
)
app.add_middleware(BabelMiddleware, babel_configs=configs)

if __name__ == "__main__":
    Babel(configs).run_cli()

1. extract messages with following command

python3 babel.py extract -d/--dir {watch_dir}

**Notice: ** watch_dir is your project root directory, where the messages will be extracted.

2. Add your own language locale directory, for instance fa.

python3 babel.py init -l fa

3. Go to ./lang/Fa/.po and add your translations.

4. compile all locale directories. python3 babel.py compile

from fastapi import FastAPI, Request
from fastapi_babel import _
from .babel import babel

app = FastAPI()
app.add_middleware(BabelMiddleware, babel_configs=BabelConfigs(
    ROOT_DIR=__file__,
    BABEL_DEFAULT_LOCALE="en",
    BABEL_TRANSLATION_DIRECTORY="lang",
))

@app.get("/items/{id}", response_class=HTMLResponse)
async def read_item(request: Request, id: str):
    return id + _("Hello World")

5. Now you can control your translation language from the request header and the locale code. The parameter is Accept-Language.

Screenshot:

How to use Jinja In FastAPI Babel

1. Add jinja extension to babel.cfg

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

2. Here is how your main.py should look like.

main.py

from fastapi_babel import Babel, BabelConfigs, BabelMiddleware, _
from fastapi.responses import HTMLResponse
from fastapi.staticfiles import StaticFiles
from fastapi.templating import Jinja2Templates
from fastapi import FastAPI, Request

app = FastAPI()
babel_configs = BabelConfigs(
        ROOT_DIR=__file__,
        BABEL_DEFAULT_LOCALE="en",
        BABEL_TRANSLATION_DIRECTORY="lang",
)
templates = Jinja2Templates(directory="templates")
app.add_middleware(BabelMiddleware, babel_configs=babel_configs, jinja2_templates=templates)
app.mount("/static", StaticFiles(directory="static"), name="static")

@app.get("/items/{id}", response_class=HTMLResponse)
async def read_item(request: Request, id: str):
    return templates.TemplateResponse("item.html", {"request": request, "id": id})

3. Here is sample index.html file

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <h1>{{_("Hello World")}}</h1>
</body>
</html>

4. Now just follow the documentation from step 5.

5. More features like lazy gettext, please check the Wtform Example

Authors

• @Parsa Pourmhammad

Contributing

Contributions are always welcome!

Please read contributing.md to get familiar how to get started.

Please adhere to the project's code of conduct.

Feedback And Support

Please open an issue and follow the template, so the community can help you.