translationstring.Pluralizer() provides a gettext "plural forms" pluralization service.

It is called like so:

import gettext
from translationstring import Pluralizer
translations = gettext.translations(.. the right arguments ...)
pluralizer = Pluralizer(translations)

The translations argument is required; it should be an object supporting at least the Python gettext.NullTranslations API but ideally the API, which has support for domain lookups like dungettext.

The object returned will be a callable which has the following signature:

def pluralizer(singular, plural, n, domain=None, mapping=None):
    """ Pluralize """

The singular and plural arguments passed may be translation strings or unicode strings. n represents the number of elements. domain is the translation domain to use to do the pluralization, and mapping is the interpolation mapping that should be used on the result. The pluralizer will return the plural form or the singular form, translated, as necessary.


if the objects passed are translation strings, their domains and mappings are ignored. The domain and mapping arguments must be used instead. If the domain is not supplied, a default domain is used (usually messages).

If translations is None, a gettext.NullTranslations object is created for the pluralizer to use.

The translationstring.Pluralizer() function accepts an additional optional argument named policy. policy should be a callable which accepts five arguments: translations, singular and plural, n and domain. It must perform the actual pluralization lookup. If policy is None, the translationstring.dungettext_policy() policy will be used.