If you have the config.pck file for a version 2.1 mailing list, you can import that into an existing mailing list in Mailman 3.0.
>>> from mailman.commands.cli_import import Import21
>>> command = Import21()
>>> class FakeArgs:
... listname = None
... pickle_file = None
>>> class FakeParser:
... def error(self, message):
... print(message)
>>> command.parser = FakeParser()
You must specify the mailing list you are importing into, and it must exist.
>>> command.process(FakeArgs)
List name is required
>>> FakeArgs.listname = ['import@example.com']
>>> command.process(FakeArgs)
No such list: import@example.com
When the mailing list exists, you must specify a real pickle file to import from.
>>> mlist = create_list('import@example.com')
>>> command.process(FakeArgs)
config.pck file is required
>>> FakeArgs.pickle_file = [__file__]
>>> command.process(FakeArgs)
Not a Mailman 2.1 configuration file: .../import.rst
Now we can import the test pickle file. As a simple illustration of the import, the mailing list’s ‘real name’ has changed.
>>> from pkg_resources import resource_filename
>>> FakeArgs.pickle_file = [
... resource_filename('mailman.testing', 'config.pck')]
>>> print(mlist.display_name)
Import
>>> command.process(FakeArgs)
>>> print(mlist.display_name)
Test