The way flufl.i18n finds its catalog for an application is extensible. These are called strategies. flufl.i18n comes with a couple of fairly simple strategies. The first locates catalog files from within a package’s directory. Inside the package directory, you still need the gettext standard layout of <code>/LC_MESSAGES/<application>.mo.
For example, to use the catalog in flufl.i18n‘s testing package, you would use the PackageStrategy.
>>> from flufl.i18n import PackageStrategy >>> import flufl.i18n.testing.messages
By setting the $LANG environment variable, we can specify that the application translates into that language automatically.
>>> # The testing 'xx' language rot13's the source string. >>> import os >>> os.environ['LANG'] = 'xx'
The first argument is the application name, which must be unique among all registered strategies. The second argument is the package in which to search.
>>> strategy = PackageStrategy('flufl', flufl.i18n.testing.messages)
Once you have the desired strategy, register this with the global registry. The registration process returns an application object which can be used to look up language codes.
>>> from flufl.i18n import registry >>> application = registry.register(strategy)
The application object keeps track of a current translation catalog, and exports a method which you can bind to the ‘underscore’ function in your module globals for convenient gettext usage.
>>> _ = application._
By doing so, at run time, _() will always translate the string argument to the current catalog’s language.
>>> print(_('A test message')) N grfg zrffntr
There is also a simpler strategy that uses both the $LANG environment variable, and the $LOCPATH environment variable to set things up:
>>> os.environ['LOCPATH'] = os.path.dirname( ... flufl.i18n.testing.messages.__file__) >>> from flufl.i18n import SimpleStrategy >>> strategy = SimpleStrategy('flufl') >>> application = registry.register(strategy) >>> _ = application._ >>> print(_('A test message')) N grfg zrffntr
Strategies should be prepared to accept zero arguments when called, to produce a default translation (usually the gettext.NullTranslator). Here, we look for the ugettext() method for Python 2 and the gettext() method for Python 3:
>>> def get_ugettext(strategy): ... catalog = strategy() ... try: ... return catalog.ugettext ... except AttributeError: ... # Python 3 ... return catalog.gettext >>> print(get_ugettext(SimpleStrategy('example'))('A test message')) A test message >>> print(get_ugettext(PackageStrategy( ... 'example', flufl.i18n.testing.messages))('A test message')) A test message