best_match behavior

[azmeuk]

best_match have a behavior that feels strange to me: when a preferred regionalized locale is not available (say fr-FR), I would expect the unregionalized locale to be returned if available (fr).

# data come from a real life situation I encountered
>>> from werkzeug.datastructures import LanguageAccept
>>> accept = LanguageAccept([('fr-FR', 1), ('en-US', 0.7), ('en', 0.3)])
>>> available = ['gl', 'de', 'fr', 'es', 'nb_NO', 'en']
>>> accept.best_match(available)
'en' # <-- I would have preferred 'fr'

I am not sure if this is a bug or a wanted undocumented behavior.
What do you think?

Related tickets #1651 #450

[davidism]

It looks like #1507 is the current behavior. From my last comment there, it does seem like fr should match since fr-FR is the highest priority.

[davidism]

Converted to issue #2732

[davidism]

en is in the accept list and available list, so the exact match is preferred. This behavior won't change, although you could use your own LanguageAccept subclass to do what you want.