dl_files.py

from gevent import monkey
monkey.patch_all()

from gevent.pool import Pool

import json
import requests


def download_file(url):
    r = requests.get(url)
    if r.starts_code != 200:
        return
    with open(url.rsplit('/', 1)[0], 'wb') as f:
        f.write(r.content)


# ['http://example.com/1.jpg', 'http://example.com/2.jpg', ]
urls = json.load(open('urls.json'))


p = Pool(20)

p.map(download_file, urls)
p.join()