提供一个web服务，返回处理过的远程图片。

imgservice.py

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

__version__ = '1.0.0'

try:
    import gevent
    import gevent.queue
    import gevent.monkey
    gevent.monkey.patch_all()
except ImportError:
    pass

import sys
import time
import logging
import cStringIO

import imghdr
import requests
from PIL import Image


def application(environ, start_response):
    try:
        url = "http://www.abcd.com/captcha2.jsp?0.{}".format(time.ctime())
        r = requests.get(url)
        data = r.content
        r.close()
        imgtype = imghdr.what('', h=data)
        img = Image.open(cStringIO.StringIO(data))
        img = img.crop([0, 0, 218, 21])
        # do more by yourself
        cimg = cStringIO.StringIO()
        img.save(cimg, imgtype)
        cimg.seek(0)
        data = cimg.getvalue()
        start_response('200 OK', [('Content-Type', "image/" + imgtype),
                                  ('content-length', str(len(data)))])
        return [data]
    except Exception as e:
        raise StopIteration


def run_wsgi_app(address, app):
    try:
        from gunicorn.app.wsgiapp import WSGIApplication
        class GunicornApplication(WSGIApplication):
            def init(self, parser, opts, args):
                return {'bind': '%s:%d' % (address[0], int(address[1])),
                        'workers': 2,
                        'worker_class': 'gevent'}
            def load(self):
                return app
        GunicornApplication().run()
    except ImportError:
        from gevent.wsgi import WSGIServer
        WSGIServer(address, app).serve_forever()


if __name__ == '__main__':
    logging.basicConfig(level=logging.INFO, format='%(levelname)s - - %(asctime)s %(message)s', datefmt='[%b %d %H:%M:%S]')
    host, _, port = sys.argv[1].rpartition(':')
    logging.info('local python application serving at %s:%s', host, port)
    run_wsgi_app((host, int(port)), application)