Mechanize + Python: how to follow a link in a simple javascript?

问题

short: How to execute/simulate javascript redirection with python Mechanize?

location.href="http://www.site2.com/";

I've made a python script with mechanize module that looks for a link in a page and follows it.

The problem is on a particular site that when I do

br.follow_link("http://www.address1.com") 

he redirects me to this simple page:

<script language="JavaScript">{                                                                                         
    location.href="http://www.site2.com/";                                                                                           
    self.focus();                                                                                                                   
    }</script>

Now, if I do:

br = mechanize.Browser(factory=mechanize.RobustFactory())

... #other code

br.follow_link("http://www.address1.com") 
for link in br.links():   
br.follow_link(link)
print link

it doesn't prints anything, that means that there is no link in that page. But if I manually parse the page and I execute:

br.open("http://www.site2.com")

Site2 doesn't recognizes that I'm coming from "www.address1.com" and the script does not work as I would like!

Sorry if it's just a newbie question and thank you in advance!

p.s. I have br.set_handle_referer(True)

EDIT: more info: Inspecting that link with Fiddler2 it looks like:

GET http://www.site2.com/ HTTP/1.1 Host: www.site2.com Connection: keep-alive User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.94 Safari/537.4 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8 Referer: http://www.address1.com Accept-Encoding: gzip,deflate,sdch Accept-Language: it-IT,it;q=0.8,en-US;q=0.6,en;q=0.4
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Cookie: PHPSESSID=6e161axxxxxxxxxxx; user=myusername;
pass=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx; ip=79.xx.xx.xx;
agent=a220243a8b8f83de64c6204a5ef7b6eb; __utma=154746788.943755841.1348303404.1350232016.1350241320.43; __utmb=154746788.12.10.1350241320; __utmc=154999999; __utmz=154746788.134999998.99.6.utmcsr=google|utmccn=(organic)|utmcmd=organic|utmctr=%something%something%

so it seems to be a cookie problem?

回答1:

Mechanize can't deal with JavaScript, since it can't interpret it, try parsing your site manually and passing this link to, br.follow_link.

回答2:

I solved it! in this way:

    cj = cookielib.LWPCookieJar()
    br.set_cookiejar(cj)

    ...

    br.follow_link("www.address1.com")
    refe= br.geturl()
    req = urllib2.Request(url='www.site2.com')
    req.add_header('Referer', refe)
    opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj) )
    f = opener.open(req) 
    htm = f.read()
    print "\n\n", htm

回答3:

How about

br.open("http://alpha.com") 

br.follow_link("http://beta.com")

If you use br_follow_link hopefully that sets the HTTP referrer with the previous page. Whereas if you dobr.open that's like opening a new window, it doesn't set the HTTP referrer header.

---

Edit. Ok it looks like .follow_link doesn't take strings but takes a special mechanize.Link object with a property .absolute_url. You can fake that.

>>> class Fake:
...     pass
...
>>> x = Fake()
>>> x.absolute_url="http://stackoverflow.com"
>>> br.follow_link(x)
<response_seek_wrapper at 0x2937af8 whose wrapped object = <closeable_response at 0x2937f08 whose fp = <socket._fileobject object at 0x02934970>>>
>>> br.title()
'Stack Overflow'

or make a real mechanize.Link which is less hacky but more tedious.

回答4:

You could set the HTTP referrer header explicitly before making your request

br.addheaders = [('Referer', 'http://alpha.com')]
br.open("http://beta.com")

More details in the surprisingly difficult to find official docs http://wwwsearch.sourceforge.net/mechanize/doc.html

来源：https://stackoverflow.com/questions/12881423/mechanize-python-how-to-follow-a-link-in-a-simple-javascript