This is my method below that returns a dataframe

def refactorReport( df ):
    """Enhance with additional information as needed"""
    for userclass in [ 'ClassA', 'ClassB', 'ClassC' ]:
        df[ '%s_Region'%userclass ] = df[ userclass ].apply(lambda x: commutils.UserNameMapper( x ).Region() )
    return df

How do I mock this commutils.UserNameMapper( x )

I tried this but both are giving me self param expected

class DummyUserNameMapper():

    def __init__( self, thename ):
        self.thename = thename

    def Region( self ):
        print(self.thename)
        return 'Region%s'%self.thename[-1]


class ModuleTests(unittest.TestCase):

    def test_refactorReport(self):
        with mock.patch("commutils.UserNameMapper", return_value=DummyUserNameMapper):
            print(refactorReport(self.records))

    @mock.patch('commutils.UserNameMapper')
    def test_refactorReport_New(self, mockUser):
        mockUser.return_value = DummyUserNameMapper
        print(refactorReport(self.records))