secp256k1.py fails on Python 3.4

[albpal]

Error test:

import binascii
import rlp
# sha3 from module `pysha3` not `ssh3`
import sha3
from py_ecc.secp256k1 import ecdsa_raw_recover

n = 0
p = 20000000000
g = 100000
v = 1000
Tn = ''
Tp = p.to_bytes((p.bit_length()//8) + 1,byteorder='big')
Tg = g.to_bytes((g.bit_length()//8) + 1,byteorder='big')
Tt = binascii.unhexlify("687422eEA2cB73B5d3e242bA5456b782919AFc85")
Tv = v.to_bytes((v.bit_length()//8) + 1,byteorder='big')
Td = binascii.unhexlify("c0de")
transaction = [Tn, Tp, Tg, Tt, Tv, Td]
rlp_data=rlp.encode(transaction)
unsigned_message=sha3.keccak_256(rlp_data).hexdigest()
v = 28
r = int("5897c2c7c7412b0a555fb6f053ddb6047c59666bbebc6f5573134e074992d841",16)
s = int("1c71d1c62b74caff8695a186e2a24dd701070ba9946748318135e3ac0950b1d4",16)
ecdsa_raw_recover(unsigned_message, (v, r, s))

Error message:

Traceback (most recent call last):
File "", line 1, in
File "/home/apalau/python3.4/lib64/python3.4/site-packages/py_ecc/secp256k1/secp256k1.py", line 132, in ecdsa_raw_recover
z = bytes_to_int(msghash)
File "/home/apalau/python3.4/lib64/python3.4/site-packages/py_ecc/secp256k1/secp256k1.py", line 21, in bytes_to_int
o = (o << 8) + safe_ord(b)
TypeError: unsupported operand type(s) for +: 'int' and 'str'

On Python 2.7 the same ecdsa_raw_recover(unsigned_message, (v, r, s)) works well.