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#!/usr/bin/python
# coding: utf-8
import urllib
import urllib2
from multiprocessing import Pool
import Queue, threading
reg_nos = [16738, 17288, 18162, 18776, 18868, 19116, 19223, 19505];
pdf_url = 'http://www.mapa.es/agricultura/pags/fitos/registro/sustancias/pdf/%s.pdf'
def fetch_url(url, params={}):
return urllib2.urlopen(url).read()
def save_url_as_file(url, filename):
open(filename,'wb').write(fetch_url(url))
def download_pdf(reg_no):
f = '%d.pdf' % reg_no
save_url_as_file(pdf_url % reg_no, f)
print "\t- %s downloaded" % f
# tests
def single(regs):
for u in regs:
download_pdf(u)
def multi(regs, nprocesses=4):
pool = Pool(processes=nprocesses)
pool.map_async(download_pdf, regs).get()
def threaded(regs, nthreads=4):
# ripped from http://www.dabeaz.com/generators/Generators.pdf
def consumer(q):
while True:
item = q.get()
if not item: break
download_pdf(item)
in_q = Queue.Queue()
# start threads
ths = [threading.Thread(target=consumer,args=(in_q,))
for th in xrange(nthreads)]
for x in ths: x.start()
# put files to download
for i in regs:
in_q.put(i)
# put end guards
for th in xrange(nthreads): in_q.put(None)
# wait to finish
for x in ths: x.join()
if __name__ == '__main__':
from timeit import Timer
t = Timer("single(reg_nos)", "from __main__ import single, reg_nos")
print t.timeit(number=1)
t = Timer("multi(reg_nos)", "from __main__ import multi, reg_nos")
print t.timeit(number=1)
t = Timer("threaded(reg_nos)", "from __main__ import threaded, reg_nos")
print t.timeit(number=1)
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