TypeError: unsupported operand type(s) for ^: 'int' and 'str' in packet.py

[liujing2048]

hello, i am use python 3.6 and pyrad 2.4 In a docker environment
I use RADPERF (similar to RADClient in Freradius) tools for Pyrad to test the pressure test, and then there will be the following problems

radius-1 | Traceback (most recent call last):
radius-1 | File "main.py", line 4, in
radius-1 | start_socket()
radius-1 | File "/var/radius/mypyrad.py", line 238, in start_socket
radius-1 | srv.Run()
radius-1 | File "/usr/local/lib/python3.6/site-packages/pyrad/server.py", line 339, in Run
radius-1 | self._ProcessInput(fdo)
radius-1 | File "/usr/local/lib/python3.6/site-packages/pyrad/server.py", line 314, in _ProcessInput
radius-1 | self._HandleAuthPacket(pkt)
radius-1 | File "/usr/local/lib/python3.6/site-packages/pyrad/server.py", line 222, in _HandleAuthPacket
radius-1 | self.HandleAuthPacket(pkt)
radius-1 | File "/var/radius/mypyrad.py", line 85, in HandleAuthPacket
radius-1 | password = get_password(pkt)
radius-1 | File "/var/radius/mypyrad.py", line 53, in get_password
radius-1 | return pkt.PwDecrypt(pkt['Password'][0]) # pap
radius-1 | File "/usr/local/lib/python3.6/site-packages/pyrad/packet.py", line 712, in PwDecrypt
radius-1 | pw += bytes((hash[i] ^ buf[i],))
radius-1 | TypeError: unsupported operand type(s) for ^: 'int' and 'str'

What I want to add is：
1）During the test, the command used is：
echo "User-Name = user_test,User-Password = 123" | radperf -c 3000 -x -s 192.168.88.101:1812 auth vpdn
2）Not every test will occur, but the chance of appearing is very high

How can I fix this error myself? Thanks