[Jellby]

That works for __copyright__, which is defined outside the class, but not for version, which is inside:

from __future__ import (unicode_literals, division, absolute_import, print_function)

__license__   = 'GPL v3'
__copyright__ = '2014, Jellby <jellby@yahoo.com>'
__docformat__ = 'restructuredtext en'

from calibre.customize import InterfaceActionBase

load_translations()

class PrincePDFPlugin(InterfaceActionBase):
    name                    = _('Prince PDF')
    description             = _('Converts to PDF using the Prince software (third-party)')
    supported_platforms     = ['linux', 'windows']
    author                  = 'Jellby'
    version                 = (1, 1, 3)
    minimum_calibre_version = (1, 16, 0)
    actual_plugin           = 'calibre_plugins.prince_pdf.ui:InterfacePlugin'

...

(ImportError: cannot import name version)

I must be doing something wrong.