python直接下载图片到内存

1. 使用requests（推荐）

from PIL import Image
import requests
Image.open(requests.get(url, stream=True).raw)

2. 使用StringIO

from PIL import Image
from StringIO import StringIO
import requests

r = requests.get("http://a/b/c")
im = Image.open(StringIO(r.content))
im.size

# =======================

from PIL import Image
import urllib2 as urllib
from StringIO import StringIO

fd = urllib.urlopen("http://a/b/c")
im = Image.open(StringIO(fd.read()))
im.size

3. 使用io.BytesIO

from PIL import Image
import urllib2 as urllib
import io

fd = urllib.urlopen("http://a/b/c")
image_file = io.BytesIO(fd.read())
im = Image.open(image_file)

 ====

#!/usr/bin/env python
# coding=utf-8

from urllib2 import urlopen
import random
import time

from multiprocessing import Pool 

url_root = 'http://www.beianbeian.com/gaoji/validate_code?a='
cnt = 1000

def download_img(url, path='static/uploads/'):
    global cnt
    while cnt < 2000:
        fname = path + "BA%d.jpg" % cnt
        with open(fname, 'wb') as fw:
            try:
                fw.write(urlopen(url).read())
                print fname, 'done'
                cnt += 1
            except Exception as e:
                print 'Error', e
                continue

        time.sleep(0.2)

if __name__ == "__main__":

    pool = Pool(processes=4)
    for i in range(10):
        randNum = random.random()
        url = url_root + str(randNum)
        pool.apply(download_img, args=(url,))
        pool.close()
        pool.join()