下面的python代码通过MySQLdb模块链接mysql数据库，然后打开数据库，并通过sql语句查询mysql的版本号，最后关闭数据库连接

#!/usr/bin/python 
  
import MySQLdb 
  
# Open database connection 
db = MySQLdb.connect("localhost","testuser","test123","TESTDB" ) 
  
# prepare a cursor object using cursor() method 
cursor = db.cursor() 
  
# execute SQL query using execute() method. 
cursor.execute("SELECT VERSION()") 
  
# Fetch a single row using fetchone() method. 
data = cursor.fetchone() 
  
print "Database version : %s " % data 
  
# disconnect from server 
db.close()