Question

I am trying to filter a value from a string using regular expressions, for example filtering out the URL from a <a href=""/> tag.

<a href="http://www.example.com">

I looked through the re library and the regexp that should match the string should be

r'<a href="(.*)">'

Now what’s the best way to save this value into a variable?

Answer 1

You shouldn’t parse html with regex, but since you said that is only an example…
If you expect to always find a match:

try:
    foo = re.search(r'<a href="(.*)">', text).group(1)
except AttributeError:
    foo = None

If you don’t know if it will match:

match = re.search(r'<a href="(.*)">', text)
if match:
    foo = match.group(1)
else:
    foo = None