Edgewall Software
Last modified 7 years ago Last modified on 06/20/07 16:17:57

Distutils/Setuptools Integration

Babel provides commands for integration into setup.py scripts, based on either the distutils package that is part of the Python standard library, or the third-party setuptools package.

These commands are available by default when Babel has been properly installed, and setup.py is using setuptools. For projects that use plain old distutils, the commands need to be registered explicitly, for example:

from distutils.core import setup
from babel.messages import frontend as babel
setup(
    ...
    cmdclass = {'compile_catalog': babel.compile_catalog,
                'extract_messages': babel.extract_messages,
                'init_catalog': babel.init_catalog,
                'update_catalog': babel.update_catalog}
)

1   compile_catalog

The compile_catalog command is similar to the GNU msgfmt tool, in that it takes a message catalog from a PO file and compiles it to a binary MO file.

If the command has been correctly installed or registered, a project's setup.py script should allow you to use the command:

$ ./setup.py compile_catalog --help
Global options:
  --verbose (-v)  run verbosely (default)
  --quiet (-q)    run quietly (turns verbosity off)
  --dry-run (-n)  don't actually do anything
  --help (-h)     show detailed help message

Options for 'compile_catalog' command:
   ...

Running the command will produce a binary MO file:

$ ./setup.py compile_catalog --directory foobar/locale --locale pt_BR
running compile_catalog
compiling catalog to foobar/locale/pt_BR/LC_MESSAGES/messages.mo

1.1   Options

The compile_catalog command accepts the following options:

Option Description
--domain domain of the PO file (defaults to lower-cased project name)
--directory (-d) name of the base directory
--input-file (-i) name of the input file
--output-file (-o) name of the output file
--locale (-l) locale for the new localized string
--use-fuzzy (-f) also include "fuzzy" translations
--statistics print statistics about translations

If directory is specified, but output-file is not, the default filename of the output file will be:

<directory>/<locale>/LC_MESSAGES/<domain>.mo

If neither the input_file nor the locale option is set, this command looks for all catalog files in the base directory that match the given domain, and compiles each of them to MO files in the same directory.

These options can either be specified on the command-line, or in the setup.cfg file.

2   extract_messages

The extract_messages command is comparable to the GNU xgettext program: it can extract localizable messages from a variety of difference source files, and generate a PO (portable object) template file from the collected messages.

If the command has been correctly installed or registered, a project's setup.py script should allow you to use the command:

$ ./setup.py extract_messages --help
Global options:
  --verbose (-v)  run verbosely (default)
  --quiet (-q)    run quietly (turns verbosity off)
  --dry-run (-n)  don't actually do anything
  --help (-h)     show detailed help message

Options for 'extract_messages' command:
   ...

Running the command will produce a PO template file:

$ ./setup.py extract_messages --output-file foobar/locale/messages.pot
running extract_messages
extracting messages from foobar/__init__.py
extracting messages from foobar/core.py
...
writing PO template file to foobar/locale/messages.pot

2.1   Method Mapping

The mapping of file patterns to extraction methods (and options) can be specified using a configuration file that is pointed to using the --mapping-file option shown above. Alternatively, you can configure the mapping directly in setup.py using a keyword argument to the setup() function:

setup(...
    message_extractors = {
        'foobar': [
            ('**.py',                'python', None),
            ('**/templates/**.html', 'genshi', None),
            ('**/templates/**.txt',  'genshi', {
                'template_class': 'genshi.template:TextTemplate'
            })
        ],
    },
    ...
)

2.2   Options

The extract_messages command accepts the following options:

Option Description
--charset charset to use in the output file
--keywords (-k) space-separated list of keywords to look for in addition to the defaults
--no-default-keywords do not include the default keywords
--mapping-file (-F) path to the mapping configuration file
--no-location do not include location comments with filename and line number
--omit-header do not include msgid "" entry in header
--output-file (-o) name of the output file
--width (-w) set output line width (default 76)
--no-wrap do not break long message lines, longer than the output line width, into several lines
--input-dirs directories that should be scanned for messages
--sort-output generate sorted output (default False)
--sort-by-file sort output by file location (default False)
--msgid-bugs-address set email address for message bug reports
--copyright-holder set copyright holder in output
--add-comments (-c) place comment block with TAG (or those preceding keyword lines) in output file. Separate multiple TAGs with commas(,)

These options can either be specified on the command-line, or in the setup.cfg file. In the latter case, the options above become entries of the section [extract_messages], and the option names are changed to use underscore characters instead of dashes, for example:

[extract_messages]
keywords = _ gettext ngettext
mapping_file = babel.cfg
width = 80

This would be equivalent to invoking the command from the command-line as follows:

$ setup.py extract_messages -k _ -k gettext -k ngettext -F mapping.cfg -w 80

Any path names are interpreted relative to the location of the setup.py file. For boolean options, use "true" or "false" values.

3   init_catalog

The init_catalog command is basically equivalent to the GNU msginit program: it creates a new translation catalog based on a PO template file (POT).

If the command has been correctly installed or registered, a project's setup.py script should allow you to use the command:

$ ./setup.py init_catalog --help
Global options:
  --verbose (-v)  run verbosely (default)
  --quiet (-q)    run quietly (turns verbosity off)
  --dry-run (-n)  don't actually do anything
  --help (-h)     show detailed help message

Options for 'init_catalog' command:
  ...

Running the command will produce a PO file:

$ ./setup.py init_catalog -l fr -i foobar/locales/messages.pot \
                         -o foobar/locales/fr/messages.po
running init_catalog
creating catalog 'foobar/locales/fr/messages.po' based on 'foobar/locales/messages.pot'

3.1   Options

The init_catalog command accepts the following options:

Option Description
--domain domain of the PO file (defaults to lower-cased project name)
--input-file (-i) name of the input file
--output-dir (-d) name of the output directory
--output-file (-o) name of the output file
--locale locale for the new localized string

If output-dir is specified, but output-file is not, the default filename of the output file will be:

<output_dir>/<locale>/LC_MESSAGES/<domain>.po

These options can either be specified on the command-line, or in the setup.cfg file.

4   update_catalog

The update_catalog command is basically equivalent to the GNU msgmerge program: it updates an existing translations catalog based on a PO template file (POT).

If the command has been correctly installed or registered, a project's setup.py script should allow you to use the command:

$ ./setup.py update_catalog --help
Global options:
  --verbose (-v)  run verbosely (default)
  --quiet (-q)    run quietly (turns verbosity off)
  --dry-run (-n)  don't actually do anything
  --help (-h)     show detailed help message

Options for 'update_catalog' command:
  ...

Running the command will update a PO file:

$ ./setup.py update_catalog -l fr -i foobar/locales/messages.pot \
                            -o foobar/locales/fr/messages.po
running update_catalog
updating catalog 'foobar/locales/fr/messages.po' based on 'foobar/locales/messages.pot'

4.1   Options

The update_catalog command accepts the following options:

Option Description
--domain domain of the PO file (defaults to lower-cased project name)
--input-file (-i) name of the input file
--output-dir (-d) name of the output directory
--output-file (-o) name of the output file
--locale locale for the new localized string
--ignore-obsolete do not include obsolete messages in the output
--no-fuzzy-matching (-N) do not use fuzzy matching
--previous keep previous msgids of translated messages

If output-dir is specified, but output-file is not, the default filename of the output file will be:

<output_dir>/<locale>/LC_MESSAGES/<domain>.po

If neither the input_file nor the locale option is set, this command looks for all catalog files in the base directory that match the given domain, and updates each of them.

These options can either be specified on the command-line, or in the setup.cfg file.


See also: User Guide, Working with Message Catalogs, Command-Line Interface, Documentation