我在python2中遇到此'__getitem__'类型错误，但是我不知道如何解决

Question

当我按照文章来解决googleCTF挑战时， 我收到此类型错误：

[+] Opening connection to fridge-todo-list.ctfcompetition.com on port 1337: Done
Traceback (most recent call last):
  File "./exploit.py", line 18, in <module>
    write_addr = res.split(':', 1)[1][1:].ljust(8, chr[0])
TypeError: 'builtin_function_or_method' object has no attribute '__getitem__'
[*] Closed connection to fridge-todo-list.ctfcompetition.com port 1337

当我使用[]访问元素时，我知道调用了 getitem ，但是我不知道如何解决。

本文使用python2。

#!/usr/bin/env python2
from pwn import *
from struct import unpack, pack

错误出现的扇区是：

# store "write_addr"
res = r.readuntil("Hi haxxor,").splitlines()[0]
write_addr = res.split(':', 1)[1][1:].ljust(8, chr[0])
write_addr = unpack("<Q", write_addr)[0]
print write_addr

仅供参考，我看到的内容是这样的： Integer Overflow Exploit | Google CTF #7