python - can we use XPath with BeautifulSoup?

Question

I am using BeautifulSoup to scrape an URL and I had the following code

import urllib
import urllib2
from BeautifulSoup import BeautifulSoup

url =  "http://www.example.com/servlet/av/ResultTemplate=AVResult.html"
req = urllib2.Request(url)
response = urllib2.urlopen(req)
the_page = response.read()
soup = BeautifulSoup(the_page)
soup.findAll('td',attrs={'class':'empformbody'})

Now in the above code we can use findAll to get tags and information related to them, but I want to use XPath. Is it possible to use XPath with BeautifulSoup? If possible, can anyone please provide me an example code so that it will be more helpful?

Answer 1

Nope, BeautifulSoup, by itself, does not support XPath expressions.

An alternative library, lxml, does support XPath 1.0. It has a BeautifulSoup compatible mode where it'll try and parse broken HTML the way Soup does. However, the default lxml HTML parser does just as good a job of parsing broken HTML, and I believe is faster.

Once you've parsed your document into an lxml tree, you can use the .xpath() method to search for elements.

try:
    # Python 2
    from urllib2 import urlopen
except ImportError:
    from urllib.request import urlopen
from lxml import etree

url =  "http://www.example.com/servlet/av/ResultTemplate=AVResult.html"
response = urlopen(url)
htmlparser = etree.HTMLParser()
tree = etree.parse(response, htmlparser)
tree.xpath(xpathselector)

There is also a dedicated lxml.html() module with additional functionality.

Note that in the above example I passed the response object directly to lxml, as having the parser read directly from the stream is more efficient than reading the response into a large string first. To do the same with the requests library, you want to set stream=True and pass in the response.raw object after enabling transparent transport decompression:

import lxml.html
import requests

url =  "http://www.example.com/servlet/av/ResultTemplate=AVResult.html"
response = requests.get(url, stream=True)
response.raw.decode_content = True
tree = lxml.html.parse(response.raw)

Of possible interest to you is the CSS Selector support; the CSSSelector class translates CSS statements into XPath expressions, making your search for td.empformbody that much easier:

from lxml.cssselect import CSSSelector

td_empformbody = CSSSelector('td.empformbody')
for elem in td_empformbody(tree):
    # Do something with these table cells.

Coming full circle: BeautifulSoup itself does have very complete CSS selector support:

for cell in soup.select('table#foobar td.empformbody'):
    # Do something with these table cells.