TypeError: 'in <string>' requires string as left operand, not bytes

[JoffreyN]

Traceback (most recent call last):
File "<pyshell#1>", line 1, in
print(conn.invoke(interface, method, param.encode('ascii')))
File "D:\Program Files\Python36\lib\site-packages\dubbo_telnet-1.0.1b3-py3.6.egg\dubbo_telnet_init_.py", line 84, in invoke
return self.do(cmd)
File "D:\Program Files\Python36\lib\site-packages\dubbo_telnet-1.0.1b3-py3.6.egg\dubbo_telnet_init_.py", line 65, in do
tn.write('\n')
File "D:\Program Files\Python36\lib\telnetlib.py", line 287, in write
if IAC in buffer:
TypeError: 'in ' requires string as left operand, not bytes