Replace SRC of all IMG elements using Parser

Question

I am looking for a way to replace the SRC attribute in all IMG tags not using Regular expressions. (Would like to use any out-of-the box HTML parser included with default Py

Answer 1

Here is a pyparsing approach to your problem. You'll need to do your own code to transform the http src attribute.

from pyparsing import *
import urllib2

imgtag = makeHTMLTags("img")[0]

page = urllib2.urlopen("http://www.yahoo.com")
html = page.read()
page.close()

# print html

def modifySrcRef(tokens):
    ret = "<img"
    for k,i in tokens.items():
        if k in ("startImg","empty"): continue
        if k.lower() == "src":
            # or do whatever with this
            i = i.upper() 
        ret += ' %s="%s"' % (k,i)
    return ret + " />"

imgtag.setParseAction(modifySrcRef)

print imgtag.transformString(html)

The tags convert to:

<img src="HTTP://L.YIMG.COM/A/I/WW/BETA/Y3.GIF" title="Yahoo" height="44" width="232" alt="Yahoo!" />
<a href="r/xy"><img src="HTTP://L.YIMG.COM/A/I/WW/TBL/ALLYS.GIF" height="20" width="138" alt="All Yahoo! Services" border="0" /></a>

Answer 2

There is a HTML parser in the Python standard library, but it’s not very useful and it’s deprecated since Python 2.6. Doing this kind of things with BeautifulSoup is really easy:

from BeautifulSoup import BeautifulSoup
from os.path import basename, splitext
soup = BeautifulSoup(my_html_string)
for img in soup.findAll('img'):
    img['src'] = 'cid:' + splitext(basename(img['src']))[0]
my_html_string = str(soup)