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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 get_database_size(db_user, db_name, localhost=False):
 """ Returns the total size for the given database role and name. :param db_user: String representing the database role. :param db_name: String representing the database name. """

    localhost_part = ''
    if localhost:
        localhost_part = '-h localhost '
    cmd = 'psql {0}-U {1} -c "select pg_database_size(\'{2}\');"'.format(
        localhost_part, db_user, db_name)
    total = getoutput(cmd).split()[2]
    return int(total)