python, phantomjs and yslow

pyslow.py

import sys, os, logging, subprocess, json
import gevent


logging.basicConfig(level=logging.DEBUG)

APP_ROOT = os.path.dirname(os.path.realpath(__file__))
YSLOW = os.path.join(APP_ROOT, 'js/yslow.js')
PHANTOMJS = "/usr/local/bin/phantomjs"

def yslow(url):
    try:
        f = subprocess.Popen([PHANTOMJS, YSLOW, "--info grade", url], stdout=subprocess.PIPE,
                stderr=subprocess.STDOUT, shell=False)
        out = f.communicate()[0]
        return json.loads(out)
    except Exception, e:
        logging.fatal("Error parsing message: %s" % e)

def main():
    if len(sys.argv) < 2:
        print "needs url"
        sys.exit(-1)

    url = sys.argv[1]
    d = yslow(url)
    scores = d['g'].keys()
    print "Load time: %s" % d['lt']
    print "Size: %s" % d['w']
    print "Overall score: %s" % d['o']

    for k in scores:
        print "%s : %s" % (k, d['g'][k].get(u'score', None))


if __name__ == "__main__":
    main()