The format() method is the new, preferred syntax for string formatting in Python 3. The old style % operation has been deprecated. As of now, FreeIPA's gettext helpers only support % and not format.

The improvement is required to fix some bad translation, see https://github.com/freeipa/freeipa/pull/1997

Add format()

Add format method to ipalib.text (untested example):

class Gettext:
     ...
    def format(self, *args, **kwargs):
        return unicode(self).format(*args, **kwargs)

class NGettext:
     ...
    def format(self, **kwargs):
        count = kwargs['count']
        return self(count).format(**kwargs)

class ConcatenatedLazyText:
     ...
    def format(self, *args, **kwargs):
        return unicode(self).format(*args, **kwargs)

Add tests

Add tests for format to ipatests.test_ipalib.test_text. You can just copy and modify the test_mod tests for all three classes.