Ping

from threading import Thread
import socket
import csv
import os

def program():
    nThreads = 20

    def runthread(urls,inds,index):
        outfile = open('output' + str(index) + '.csv','wb')
        out = csv.writer(outfile)
        for i in xrange(0,len(urls)):
            url = urls[i]
            try:
                ip = socket.gethostbyname(url)
            except:
                ip = 'NOT AVAILABLE'
                s = '--------- ERROR: ' + url + '\n'
            else:
                s = url + '\n'
                s += 'IP: ' + ip + '\n'
                s += 'row: ' + str(inds[i]) + '\n'
            s += '--------------------------\n'
            print s
            out.writerow([inds[i],url,ip])
            outfile.flush()

    print '--------------------------'

    threadinputs = [[[], []] for i in xrange(0,nThreads)]

    ind = 1
    for row in csv.reader(open('input.csv','rb')):
        thread = (ind-1) % nThreads
        threadinputs[thread][0].append(row[0])
        threadinputs[thread][1].append(ind)
        ind += 1

    threads = []

    for t in threadinputs:
        ind = len(threads)
        threads.append(Thread(target=runthread, args=(t[0],t[1],ind)))
        threads[-1].setDaemon(True)
        threads[-1].start()

    for t in threads:
        t.join()

    vals = []
    for i in xrange(0,nThreads):
        for row in csv.reader(open('output' + str(i) + '.csv','rb')):
            vals.append([int(row[0]),row[1],row[2]])
        os.remove('output' + str(i) + '.csv')
    vals = sorted(vals)

    outwriter = csv.writer(open('output.csv','wb'))
    for val in vals:
        outwriter.writerow(val[1:])

    print "DONE"

program()