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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def create_database(destroy_existing=False):

 """ Create db and tables if it doesn't exist """

    if not os.path.exists(DB_NAME):
        logger.info('Create database: {0}'.format(DB_NAME))
        open(DB_NAME, 'a').close()
        Show.create_table()
        Episode.create_table()
        Setting.create_table()