can't concatenate strings in Python-3

Question

when running this script in Python-3:

#!/usr/bin/python
# -*- coding: utf-8 -*-
import socket
import random
import os
import threading
import sys

class bot(threading.Thread):
   def __init__( self, net, port, user, nick, start_chan ): 
       self.id= random.randint(0,1000)
       self.irc = socket.socket ( socket.AF_INET, socket.SOCK_STREAM )
       self.irc_connect ( net, port )
       self.irc_set_user( user,nick )
       self.irc_join( start_chan )
       self.finnish=False
       threading.Thread.__init__(self)

   def run( self ):
       while not self.finnish:
           serv_data_rec = self.irc.recv ( 4096 )
           if serv_data_rec.find ( "PING" ) != -1:
               self.irc.send( "PONG"+ serv_data_rec.split() [ 1 ] + "\r\n" )

           elif serv_data_rec.find("PRIVMSG")!= -1:
               line = serv_data_rec.split( "!" ) [ 0 ] + " :" + serv_data_rec.split( ":" ) [ 2 ]

               self.irc_log( line )
               self.irc_message( line )

   def stop( self ):
       self.finnish = True
       self.irc_quit()

   def irc_connect( self, net, port ):
       self.net = net
       self.port = port
       self.irc.connect ( ( net, port ) )

   def irc_set_user( self, user, nick ):
       self.user = user
       self.nick = nick
       self.irc.send( "NICK " + nick + "\r\n" )
       self.irc.send( "USER " + user + "\r\n" )

   def irc_join( self, chan ):
       self.chan = chan
       self.irc.send( "JOIN " + chan + "\r\n" )

   def irc_message( self, msg ):
       self.irc.send( "PRIVMSG " + self.chan+" " + msg + " \r\n" )

   def irc_message_nick( self, msg , nick):
       self.irc.send( "PRIVMSG " + self.chan+" " + nick + " " + msg + " \r\n" )

   def irc_ping( self ):
       self.irc.send("PING :" + self.net)

   def irc_log( self, line ):
       if not os.path.exists("./logs"):
           os.makedirs("./logs")
       f = open("./logs/" + self.net + self.chan + "#" + "% s" %self.id,'a')
       try:
           f.write( line )
       finally:
           f.close()

   def irc_quit( self ):
       self.irc.send( "QUIT\r\n" )

   def irc_quit_msg(self, msg):
       self.irc.send( "QUIT :" + msg + "\r\n" )

def main():
    bot_main= bot( "irc.freenode.net",6667,"botty botty botty :Python IRC","hello_nick","#martin3333" )
    bot_main.start()
    while 1:
        inp = raw_input()
        if inp =="!QUIT": 
            bot_main.stop()
            break
    sys.exit(0)

if __name__ == '__main__': main()

I get the following traceback:

File "./hatebozzer.py", line 84, in <module>
    if __name__ == '__main__': main()
File "./hatebozzer.py", line 75, in main
    bot_main= bot( "irc.freenode.net",6667,"botty botty botty :Python IRC","hello_nick","#martin3333" )
File "./hatebozzer.py", line 14, in __init__
    self.irc_set_user( user,nick )
File "./hatebozzer.py", line 43, in irc_set_user
    self.irc.send( "NICK " + nick + "\r\n" )
TypeError: 'str' does not support the buffer interface

I know that strings are treated completly differently in Python 3, but I am not trying to convert strings or do anything exotic. I just want to concatenate them, so what did I wrong here?

It's not the concatenation, `.send()` receives the string you want it to receive. It just isn't happy with getting a string. — , May 01 '13 at 14:57
See [this answer](http://stackoverflow.com/a/2411981/264775) - strings are handled differently between Python 3 and Python 2. — thegrinner, May 01 '13 at 15:01

unutbu · Accepted Answer · 2013-05-01T15:09:39.843

5

send wants a sequence of bytes as its argument.

In Python2, "NICK " + nick + "\r\n" is a sequence of bytes. But in Python3, it is a str, which in Python2 would have been called a unicode. In Python3 this is not a sequence of bytes.

In Python3, to convert the str to a sequence of bytes, apply an encoding:

("NICK " + nick + "\r\n").encode('utf-8')

or (to follow best practices, use format instead of +):

"NICK {n}\r\n".format(n=nick).encode('utf-8')

edited May 01 '13 at 15:09

answered May 01 '13 at 14:58

unutbu

842,883
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1,785
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TypeError: Can't convert 'bytes' object to str implicitly, but we want to convert str to bytes or aren't we? – Martin Erhardt May 01 '13 at 15:07
1

Sorry, I forgot parentheses around the `str`. – unutbu May 01 '13 at 15:09
Thanks, but I probably won't love Python 3 ... ^^ – Martin Erhardt May 01 '13 at 15:11

score 2 · Answer 2 · answered May 01 '13 at 14:58

2

The code you link to is not Python 3 compatible.

You are trying to send Unicode strings to a socket, which expects bytes instead. The code also uses raw_input() which was renamed to input in Python 3.

Use Python 2 to run that code instead.

answered May 01 '13 at 14:58

Martijn Pieters

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can't concatenate strings in Python-3

2 Answers2