Extraction Method Mapping

So django-babel comes with an extraction method plugin that can extract localizable messages from Django template files. Python is supported out of the box by Babel. To use this extraction functionality, create a file called babel.cfg in your project directory (the directory above your project package), with the content:

[django: templates/**.*]
[django: mypkg/*/templates/**.*]
[python: mypkg/**.py]

This instructs Babel to look for any files in the top-level templates directory, or any files in application templates directories, and use the extraction method named “django” to extract messages from those template files. You’ll need to adjust those glob patterns to wherever you my be storing your templates.

Also, any files with the extension .py inside your package directory (replace “mypkg” with the actual name of your Django project package) are processed by the “python” extraction method.

If you don’t use setuptools, or for some reason haven’t installed django-babel using setuptools/pip, you’ll need to define what function the extraction method “django” maps to. This is done in an extra section at the top of the configuration file:

[extractors]
django = django_babel.extract:extract_django

The encoding of the templates is assumed to be UTF-8. If you are using a different encoding, you will need to specify it in the configuration. For example:

[django: templates/**.*]
encoding = iso-8859-1

Running the Extraction Process

Once you’ve set up the configuration file, the actual extraction is performed by executing the command-line program pybabel which is installed alongside the Babel package:

$ cd projectdir
$ pybabel extract -F babel.cfg -o mypkg/locale/django.pot .

This creates the PO file template in mypkg/locale/django.pot.

Creating and Updating Translations Catalogs

If you don’t already have translation catalogs, you need to create them. This is done using the pybabel init command:

$ pybabel init -D django -i mypkg/locale/django.pot -d mypkg/locale -l en_US
$ pybabel init -D django -i mypkg/locale/django.pot -d mypkg/locale -l de_DE

This should create two files: mypkg/locale/en_US/django.po and mypkg/locale/de_DE/django.po. These files are where you put the actual translations.

When you modify your Python source files or your templates, you genereally need to sync the translation catalogs. For that, you first perform a fresh extraction as described in the previous section, so that the django.pot file gets updated.

Then, you run the pybabel update command to merge the changes into the translation catalogs:

`bash $ pybabel update -D django -i mypkg/locale/django.pot -d mypkg/locale `

This will update all the .po files found in the mypkg/locale directory.

Compiling Translations Catalogs

Finally, you need to compile those .po files to binary .mo files. Use the pybabel compile command for that:

$ pybabel compile -D django -d mypkg/locale

Add the --statistics option to get information about the completeness of your translations:

$ pybabel compile -D django -d mypkg/locale --statistics

Using setup.py

Much of the above process can be automated if you add a setup.py script to your project and use the distutils/setuptools commands that come with Babel. This is described at Distutils/Setuptools Integration.

datefmt

Renders a string representation of a date.

• Input: datetime.date, datetime.datetime, or a float/int timestamp

• Parameters: the format name or pattern (optional)

Assuming that book.pubdate returns a datetime.date or datetime.datetime object:

{{ book.pubdate|datefmt:"short" }}

would render: 4/1/07, and

{{ book.pubdate|datefmt:"E, MMM dd yyyy GGG" }}

would render: Sun, Apr 01 2007 AD

datetimefmt

Renders a string representation of a date and time.

• Input: datetime.datetime, or a float/int timestamp

• Parameters: the format name or pattern (optional)

Examples:

{{ book.pubdate|datetimefmt:"short" }}

would render: 4/1/07 3:30 PM, and

{{ book.pubdate|datetimefmt:"E, MMM dd yyyy GGG' - 'HH:mm:ss'" }}

would render: Sun, Apr 01 2007 AD - 15:30:00

timefmt

Renders a string representation of a time.

• Input: datetime.datetime, datetime.time, or a float/int timestamp

• Parameters: the format name or pattern (optional)

Examples:

{{ book.pubdate|timefmt:"short" }}

would render: 3:30 PM, and

{{ book.pubdate|timefmt:"h 'o''clock' a'" }}

would render: 3 o’clock PM

decimalfmt

Renders a string representation of a decimal number.

• Input: a Decimal object, or a float/int/long value

• Parameters: the format name or pattern (optional)

Examples:

{{ book.pagecount|decimalfmt }}

would render: 1,234, and

{{ book.pagecount|decimalfmt:"#,##0.00" }}

would render: 1,234.00

currencyfmt

Renders a number formatted as a currency value.

• Input: a Decimal object, or a float/int/long value

• Parameters: the currency code

Examples:

{{ book.price|currencyfmt:"USD" }}

would render: $49.90

percentfmt

Renders a string representation of a number as a percentage.

• Input: a Decimal object, or a float/int/long value

• Parameters: the format name or pattern (optional)

Examples:

Assuming book.rebate would return 0.15,

{{ book.rebate|percentfmt }}

would render 15%, and

{{ book.rebate|percentfmt:"#,##0.00%" }}

would render 15.00%.

scientificfmt

Renders a string representation of a number using scientific notation.

• Input: a Decimal object, or a float/int/long value

• Parameters: none

Examples:

Assuming book.numsold would return 1.000.000,

{{ book.numsold|scientificfmt }}

would render 10E5.