old_contents: #!/usr/bin/env python
  
  from __future__ import print_function
  
  import pymysql
  
  conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='', db='mysql')
  
  cur = conn.cursor()
  
  cur.execute("SELECT Host,User FROM user")
  
  print(cur.description)
  
  print()
  
  for row in cur:
     print(row)
  
  cur.close()
  conn.close()
  
new_contents: #!/usr/bin/env python
  from __future__ import print_function
  
  from tornado import ioloop, gen
  import tornado_mysql
  
  @gen.coroutine
  def main():
      conn = yield tornado_mysql.connect(host='127.0.0.1', port=3306, user='root', passwd='', db='mysql')
      cur = conn.cursor()
      yield cur.execute("SELECT Host,User FROM user")
      print(cur.description)
      print()
      for row in cur:
         print(row)
      cur.close()
      conn.close()
  
  
  ioloop.IOLoop.current().run_sync(main)
  
subject: Update example.