python mysql 1045 OperationalError: 1045, "Access denied for user root@'localhost'

Python代码：

# ^_^ coding: utf-8 ^_^

import MySQLdb

#打开数据库连接
db = MySQLdb.connect("localhost","root","zhang123","stucou")
cursor = db.cursor()
cursor.execute("SELECT VERSION()")
data = cursor.fetchone()

print "Database version: %s" %data

db.close()

报错 1045 OperationalError: 1045, "Access denied for user root@'localhost'

cmd进入mysql，执行

GRANT all privileges on stucou.* to 'root'@'localhost' IDENTIFIED BY 'zhang123' WITH GRANT OPTION;

然后执行，

SHOW GRANTS FOR 'root'@'localhost';

成功输出结果。