Python での永続的な接続のために MySQLdb で自動クライアント再接続を有効にする方法

import MySQLdb

class DB:
  conn = None

  def connect(self):
    self.conn = MySQLdb.connect()

  def query(self, sql):
    try:
      cursor = self.conn.cursor()
      cursor.execute(sql)
    except (AttributeError, MySQLdb.OperationalError):
      self.connect()
      cursor = self.conn.cursor()
      cursor.execute(sql)
    return cursor

# Example usage
db = DB()
sql = "SELECT * FROM foo"
cur = db.query(sql)
# Sleep for a long time to simulate connection timeout
time.sleep(60 * 60 * 24)
cur = db.query(sql)
# Connection is still valid and usable