Wrong num_plurals in Catalog

[denis90]

Overview Description

For tr and hu locales num_plurals is different in Catalog and plural.to_gettext.

Steps to Reproduce

from babel import Locale, plural
from babel.messages.catalog import Catalog

locale = "hu"
plural_form = Locale.parse(locale).plural_form
print "Rules: ", plural_form.rules
print "Gettext: ", plural.to_gettext(plural_form)
catalog = Catalog(locale)
print "Catalog.num_plurals: ", catalog.num_plurals

Actual Results

Rules: {u'one': u'n in 1'}
Gettext: nplurals=2; plural=(((n == 1)) ? 0 : 1)
Catalog.num_plurals: 1

Expected Results

Rules: {u'one': u'n in 1'}
Gettext: nplurals=2; plural=(((n == 1)) ? 0 : 1)
Catalog.num_plurals: 2

Reproducibility

Additional Information:

[nijel]

This is true for several other languages (eg. de, fr, en and es), it seems that the other plural form is missing for them:

>>> Locale.parse('en').plural_form.tags
frozenset(['one'])
>>> Locale.parse('es').plural_form.tags
frozenset(['one'])
>>> Locale.parse('de').plural_form.tags
frozenset(['one'])
>>> Locale.parse('fr').plural_form.tags
frozenset(['one'])

PS: Thinking more about this, I'm no longer sure this is related to original issue, but it seemed related at first look...

[akx]

Sorry for the super late reply – but better late than never, yeah?

We seem to currently have several definitions of plurals; the messages module has this hand-maintained dictionary of plural rules and Locales contain plural forms sourced from the CLDR.

In fact, it looks like list in messages has been slated for removal since 2013.

A good course of action would seem to be to make babel.messages.plurals.get_plural() use the data from the Locale object, if it's enough to make things work like they have before.

[akx]

Also, regarding the lack of other tags in the Locales, that seems to mean (and I should know, considering I've touched the code last in bc8f19e) that there are no specific rules for that tag.

All in all, you can consider the other rule to be implicit (at least in the case where there's only one available); all languages (I would think) have a way to express a plural.