Languages

Mailman is multilingual. A language manager handles the known set of languages at run time, as well as enabling those languages for use in a running Mailman instance.

>>> from mailman.interfaces.languages import ILanguageManager
>>> from zope.component import getUtility
>>> from zope.interface.verify import verifyObject

>>> mgr = getUtility(ILanguageManager)
>>> verifyObject(ILanguageManager, mgr)
True

# Make a copy of the language manager's dictionary, so we can restore it
# after the test.  Currently the test layer doesn't manage this.
>>> saved = mgr._languages.copy()

# The language manager component comes pre-populated; clear it out.
>>> mgr.clear()

A language manager keeps track of the languages it knows about.

>>> list(mgr.codes)
[]
>>> list(mgr.languages)
[]

Adding languages

Adding a new language requires three pieces of information, the 2-character language code, the English description of the language, and the character set used by the language. The language object is returned.

>>> mgr.add('en', 'us-ascii', 'English')
<Language [en] English>
>>> mgr.add('it', 'iso-8859-1', 'Italian')
<Language [it] Italian>

And you can get information for all known languages.

>>> print(mgr['en'].description)
English
>>> print(mgr['en'].charset)
us-ascii
>>> print(mgr['it'].description)
Italian
>>> print(mgr['it'].charset)
iso-8859-1

Other iterations

You can iterate over all the known language codes.

>>> mgr.add('pl', 'iso-8859-2', 'Polish')
<Language [pl] Polish>
>>> sorted(mgr.codes)
['en', 'it', 'pl']

You can iterate over all the known languages.

>>> from operator import attrgetter
>>> languages = sorted((language for language in mgr.languages),
...                    key=attrgetter('code'))
>>> for language in languages:
...     print(language.code, language.charset, language.description)
en us-ascii English
it iso-8859-1 Italian
pl iso-8859-2 Polish

You can ask whether a particular language code is known.

>>> 'it' in mgr
True
>>> 'xx' in mgr
False

You can get a particular language by its code.

>>> print(mgr['it'].description)
Italian
>>> print(mgr['xx'].code)
Traceback (most recent call last):
...
KeyError: 'xx'
>>> print(mgr.get('it').description)
Italian
>>> print(mgr.get('xx'))
None
>>> print(mgr.get('xx', 'missing'))
missing

Clearing the known languages

The language manager can forget about all the language codes it knows about.

>>> 'en' in mgr
True

>>> mgr.clear()
>>> 'en' in mgr
False

# Restore the data.
>>> mgr._languages = saved