Pygame webcam streaming client can't execute with python 3.4 - python-3.x

Question

I'm using pygame and python3.4 for stream a webcam in a Odroid board. The server is this (extracted of this post: using pygame to stream over sockets in python error ):
import socket
import pygame
import pygame.camera
import sys
import time
port = 5000
pygame.init()
serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serversocket.bind(("",port))
serversocket.listen(1)
pygame.camera.init()
webcam = pygame.camera.Camera("/dev/video1",(320,240))
webcam.start()
while True:
connection, address = serversocket.accept()
image = webcam.get_image() # capture image
data = pygame.image.tostring(image,"RGB") # convert captured image to string, use RGB color scheme
connection.sendall(data)
time.sleep(0.1)
connection.close()
The server works Ok in python and python 3.4.
But when I execute the client with python 3.4 I get the following error:
Traceback (most recent call last):
File "client.py", line 30, in
image = pygame.image.fromstring(dataset,(320,240),"RGB") # convert received image from string
TypeError: must be bytes, not str
The client is the following:
#!/usr/bin/python3
# -*- coding: utf-8 -*-
import socket
import pygame
import sys
host = "192.168.45.103"
port=5000
screen = pygame.display.set_mode((320,240),0)
while True:
clientsocket=socket.socket(socket.AF_INET, socket.SOCK_STREAM)
clientsocket.connect((host, port))
received = []
# loop .recv, it returns empty string when done, then transmitted data is completely received
while True:
#print("esperando receber dado")
recvd_data = clientsocket.recv(230400)
if not recvd_data:
break
else:
received.append(recvd_data)
#dataset = ''.join(received)
dataset = ','.join(str(v) for v in received)
image = pygame.image.fromstring(dataset,(320,240),"RGB") # convert received image from string
screen.blit(image,(0,0)) # "show image" on the screen
pygame.display.update()
# check for quit events
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
I changed the line dataset = ''.join(received) for dataset = ','.join(str(v) for v in received) because I read somwhere that in python3.x it mst be this.
The error line now is: image = pygame.image.fromstring(dataset,(320,240),"RGB")
Thanks!

Answer 1

These 2 lines appear to be plain wrong:
dataset = ','.join(received)
image = pygame.image.fromstring(dataset,(320,240),"RGB") # convert received
If dataset is to contain the binary pxel data, you should not be concatenating the bytes you receive with ",": it would simply add a lost of extraneous "," (decimal 44) bytes as garbage in your pixel data - the previous line, using "join" with an empty string would work (in Python 2.x) becuase called upon an empty string, join simply concatenates the various piece of data, which is what you want.
In Python3, handling of binary data (such as the pixel data you are receiving) has been separated from text handling - and the '""' empty string you where using is an object representing empty text - which is different from empty bytes from Python 2.x - but you can simply prefix it with a b for denoting a bytes-string (which is what you want).
All in all, try just using:
dataset = b''.join(str(v) for v in received)
image = pygame.image.fromstring(dataset,(320,240),"RGB")