GNOMEuses a version of the gettext module by James Henstridge, but this version has a slightly different API. Its documented usage was:
import gettext
cat = gettext.Catalog(domain, localedir)
_ = cat.gettext
print _('hello world')
For compatibility with this older module, the function Catalog() is an alias for the the translation() function described above.
One difference between this module and Henstridge's: his catalog objects supported access through a mapping API, but this appears to be unused and so is not currently supported.