finance.yahoo.com web scrapper in python

yahoo_scrapper.py

#!/usr/bin/env python2.7

# taken from https://www.youtube.com/user/sentdex

import time
import urllib2
from urllib2 import urlopen
from lxml import html

sp500short = ['a', 'aa', 'aapl', 'abbv', 'abc', 'abt', 'ace', 'aci', 'acn', 'act', 'adbe', 'adi', 'adm', 'adp']

def yahooKeyStats(stock):
    try:
        url = 'http://finance.yahoo.com/q/ks?s='+stock
        source = urllib2.urlopen(url).read()
        tree = html.fromstring(source)
        pbr = tree.xpath("//td[@class='yfnc_tabledata1']/text()")[5]
        return float(pbr)
    except Exception, e:
        print stock + ' not found'
        return -1


for stock in sp500short:
    val = yahooKeyStats(stock)
    if val < 0.70:
        pass
    print stock, val