How to use python urlopen scraping after a page finish loading all searching result?

Question

I am trying to scrape air ticket info(including plane info and price info, etc.) from http://flight.qunar.com/ using python3 and BeautifulSoup. Below is the python code I am using. In this code I tried to scrape flight info from Beijing(北京) to Lijiang(丽江) at 2012-07-25.

import urllib.parse
import urllib.request
from bs4 import BeautifulSoup
url = 'http://flight.qunar.com/site/oneway_list.htm'
values = {'searchDepartureAirport':'北京', 'searchArrivalAirport':'丽江', 'searchDepartureTime':'2012-07-25'}
encoded_param = urllib.parse.urlencode(values)
full_url = url + '?' + encoded_param
response = urllib.request.urlopen(full_url)
soup = BeautifulSoup(response)
print(soup.prettify())

What I get is the initial page after submit the request and the page is still loading the search results. What I want is the final page after it finish loading the searching results. So how can I achieve this goal using python?

Garrard

Answer 1

The problem is actually quite hard - the site uses dynamically generated content that gets loaded via JavaScript, however urllib gets basically only what you would get in a browser if you disabled JavaScript. So, what can we do?

Use

• Selenium or
• PhantomJS or
• Crowbar

to fully render a webpage (they are essentially headless, automated browsers for testing and scraping)

Or, if you want a (semi-)pure Python solution, use PyQt4.QtWebKit to render the page. It works approxiametly like this:

import sys
import signal

from optparse import OptionParser
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from PyQt4.QtWebKit import QWebPage

url = "http://www.stackoverflow.com"

def page_to_file(page):
    with open("output", 'w') as f:
        f.write(page.mainFrame().toHtml())
        f.close()

app = QApplication()
page = QWebPage()
signal.signal( signal.SIGINT, signal.SIG_DFL )
page.connect(page, SIGNAL( 'loadFinished(bool)' ), page_to_file)
page.mainFrame().load(QUrl(url))
sys.exit( app.exec_() )

Edit: There's a nice explanation how this works here.

Ps: You may want to look into requests instead of using urllib :)

Musteline

PyQt seems a good candidate for my problem. I will look into it. Thanks, Manuel. And one more question: is PyQt free? – Garrard

Yes, it is! On linux, just do sudo apt-get install python-qt4 libqt4-webkit - on mac and windows, you've got to download them manually (I think you have to register do download Qt, though) – Musteline

I tried PyQt. But I still got the same result as urlopen which is not what I want. – Garrard