Load all artists into the database

def run(self):
        """Load all artists into the database
        """

        df = ArtistsInputData().load()

        # rename columns
        df.rename(columns={'artistLabel': 'name',
                           'year_of_birth': 'extra_1',
                           'genderLabel': 'extra_2'},
                  inplace=True)

        # columns that exist in the data model
        columns = ['name', 'wiki_id']

        # the extended model also stores the date of birth and gender, as strings
        if config.EXTENDED:
            columns.append('extra_1')
            columns.append('extra_2')
            df['extra_1'] = df['extra_1'].astype(str)
            df['extra_2'] = df['extra_2'].astype(str)

        # keep only columns that exist in the data model
        df = df[columns]

        # append an ID column
        df['id'] = range(len(df))

        # store everything, done
        df.to_sql(name=models.Artist.__tablename__,
                  con=self.client.engine,
                  if_exists='append',
                  index=False)

        self.done()