Read value from web page using python

Start with not using urlretrieve(); you want the data, not a file.

Next, use a HTML parser. BeautifulSoup is great for extracting text from HTML.

Retrieving the page with urllib2 would be:

from urllib2 import urlopen

response = urlopen('http://url.com/')

then read the data into BeautifulSoup:

from bs4 import BeautifulSoup

soup = BeautifulSoup(response.read(), from_encoding=response.headers.getparam('charset'))

The from_encoding part there will tell BeautifulSoup what encoding the web server told you to use for the page; if the web server did not specify this then BeautifulSoup will make an educated guess for you.

Now you can search for your data:

for line in soup.find('div', {'name': 'mainbody'}).stripped_strings:
    if 'Wired:' in line:
        value = float(line.partition('Wired:')[2])
        print value

For your demo HTML snippet that gives:

>>> for line in soup.find('div', {'name': 'mainbody'}).stripped_strings:
...     if 'Wired:' in line:
...         value = float(line.partition('Wired:')[2])
...         print value
... 
17.4

This is called web scraping and there's a very popular library for doing this in Python, it's called Beautiful Soup:

http://www.crummy.com/software/BeautifulSoup/

If you'd like to do it with urllib/urllib2, you can accomplish that using regular expressions:

http://docs.python.org/2/library/re.html

Using regex, you basically use the surrounding context of your desired value as the key, then strip the key away. So in this case you might match from "Wired: " to the next newline character, then strip away the "Wired: " and the newline character.

You can run through the file, line by line using find or a regular expression to check for the value(s) you need or you can consider using scrapy to retrieve and parse the link.