TypeError:'datetime.datetime' objet n'est pas subscriptable

#!/usr/bin/env python
# coding: utf-8
import MySQLdb
import os,sys
import time
import datetime
from pyExcelerator import *

def main():
    '''get datas from mysql to excel'''
    w=Workbook()
    ws=w.add_sheet('user')

    mysql_conn=MySQLdb.connect(................,charset="utf8")
    cursor=mysql_conn.cursor()

    cursor.execute("select * from students")
    results=cursor.fetchall() 
    results_count=len(results)
    cursor.close()
    mysql_conn.close()  
    a=results_count-1
    print a
    #print results

    row=0     
    for r in results:        
        r3=[(x[0:2],x[2],x[3:]) for x in r]
        w3=datetime.strptime("%Y-%m-%d %H:%M:%S") 
        [ws.write(x[0:2],i) for i in r3]

        [ws.write(w3,i) for i in r3]
        [ws.write(x[3:],i or '') for i in r3]:       
        row+=1  
    w.save('data.xls')

if __name__ == "__main__":
    main()

Je veux récupérer les données de mysql vers excel ,mais
r3=[(x[0:2],x[2],x[3:]) for x in r] me donne TypeError:'datetime.datetime' object is not subscriptable.

Je ne sais pas comment à ce sujet, et je viens d'étude seulement 3 semaines, veuillez m'aider?