Python 2.7.13 Livestreamer Error drving me crazy

Question

I'm relatively new in python, but I'm trying to learn hard. For the last couple of days tried to solve an error on this script :

import requests
import subprocess
import json
import sys
import multiprocessing
import time
import random

channel_url = "gaming.youtube.com/game/"
processes = [5]


def get_channel():
    # Reading the channel name - passed as an argument to this script
    if len(sys.argv) >= 2:
        global channel_url
        channel_url += sys.argv[1]
    else:
        print "An error has occurred while trying to read arguments. Did you specify the channel?"
        sys.exit(1)


def get_proxies():
    # Reading the list of proxies
    try:
        lines = [line.rstrip("\n") for line in open("proxylist.txt")]
    except IOError as e:
        print "An error has occurred while trying to read the list of proxies: %s" % e.strerror
        sys.exit(1)

    return lines


def get_url():
    # Getting the json with all data regarding the stream
    try:
        response = subprocess.Popen(
            ["livestreamer.exe", "--http-header", "Client-ID=ewvlchtxgqq88ru9gmfp1gmyt6h2b93", 
            channel_url, "-j"], stdout=subprocess.PIPE).communicate()[0]
    except subprocess.CalledProcessError:
        print "An error has occurred while trying to get the stream data. Is the channel online? Is the channel name correct?"
        sys.exit(1)
    except OSError:
        print "An error has occurred while trying to use livestreamer package. Is it installed? Do you have Python in your PATH variable?"

    # Decoding the url to the worst quality of the stream
    try:
        url = json.loads(response)['streams']['audio_only']['url']
    except:
        try:
            url = json.loads(response)['streams']['worst']['url']
        except (ValueError, KeyError):
            print "An error has occurred while trying to get the stream data. Is the channel online? Is the channel name correct?"
            sys.exit(1)

    return url


def open_url(url, proxy):
    # Sending HEAD requests
    while True:
        try:
            with requests.Session() as s:
                response = s.head(url, proxies=proxy)
            print "Sent HEAD request with %s" % proxy["http"]
            time.sleep(20)
        except requests.exceptions.Timeout:
            print "  Timeout error for %s" % proxy["http"]
        except requests.exceptions.ConnectionError:
            print "  Connection error for %s" % proxy["http"]


def prepare_processes():
    global processes
    proxies = get_proxies()
    n = 0

    if len(proxies) < 1:
        print "An error has occurred while preparing the process: Not enough proxy servers. Need at least 1 to function."
        sys.exit(1)

    for proxy in proxies:
        # Preparing the process and giving it its own proxy
        processes.append(
            multiprocessing.Process(
                target=open_url, kwargs={
                    "url": get_url(), "proxy": {
                        "http": proxy}}))

        print '.',

    print ''

if __name__ == "__main__":
    print "Obtaining the channel..."
    get_channel()
    print "Obtained the channel"
    print "Preparing the processes..."
    prepare_processes()
    print "Prepared the processes"
    print "Booting up the processes..."

    # Timer multiplier
    n = 8

    # Starting up the processes
    for process in processes:
        time.sleep(random.randint(1, 5) * n)
        process.daemon = True
        process.start()
        if n > 1:
            n -= 1

    # Running infinitely
    while True:
        time.sleep(1)

ERROR :

python test999.py UCbadKBJT1bE14AtfBnsw27g
Obtaining the channel...
Obtained the channel
Preparing the processes...
An error has occurred while trying to use livestreamer package. Is it installed? Do you have Python in your PATH variable?
Traceback (most recent call last):
  File "test999.py", line 115, in <module>
    prepare_processes()
  File "test999.py", line 103, in prepare_processes
    "url": get_url(), "proxy": {
  File "test999.py", line 67, in get_url
    url = json.loads(response)['streams']['worst']['url']
UnboundLocalError: local variable 'response' referenced before assignment

1. I had tried on windows, installed all modules (and updated them ) livestreamer, rtmdump, dlls and other needed binary files.
2. On linux : installed livestreamer, requests, json and all neede modules. Still can't resolve it. Please help !

Answer 1

response = subprocess.Popen() in try clause. When it fails, no response lkocal variable. You should assign response before try,and process None that subporcess.Popen() may return.