Python youtube view bot not looking to hot

Code
import urllib

import time

pfl = raw_input('enter name of proxy text file: ')

lnk = raw_input('enter youtube video link: ')

tm = raw_input('time(in sec) between views: ')

tm = int(tm)

lnk = str(lnk)

candidate_proxies = []

f = open(pfl, 'r+')

for line in f:

    line = str(line)

    candidate_proxies.append(line)

print('loaded proxies.. starting bot')

l = 1

while True:

    for proxy in candidate_proxies:

        l = str(l)

        print('views so far: ' + l)

        print("Trying HTTP proxy " + proxy)

        try:

            result = urllib.urlopen(lnk,

                                proxies={'http': proxy})

            print("Got URL using proxy " + proxy)

        except:

            print("Trying next proxy...")

        time.sleep(tm)

        l = int(l)

        l = l + 1