How to transform hyperlink codes into normal URL strings?

I'm trying to build a blog system. So I need to do things like transforming '\n' into < br /> and transform http://example.com into < a href='http://example.com'>http://example.com< /a>

The former thing is easy - just using string replace() method

The latter thing is more difficult, but I found solution here: Find Hyperlinks in Text using Python (twitter related)

But now I need to implement "Edit Articl开发者_开发知识库e" function, so I have to do the reverse action on this.

So, how can I transform < a href='http://example.com'>http://example.com< /a> into http://example.com?

Thanks! And I'm sorry for my poor English.

Sounds like the wrong approach. Making round-trips work correctly is always challenging. Instead, store the source text only, and only format it as HTML when you need to display it. That way, alternate output formats / views (RSS, summaries, etc) are easier to create, too.

Separately, we wonder whether this particular wheel needs to be reinvented again ...

Since you are using the answer from that other question your links will always be in the same format. So it should be pretty easy using regex. I don't know python, but going by the answer from the last question:

import re

myString = 'This is my tweet check it out <a href="http://tinyurl.com/blah">http://tinyurl.com/blah</a>'

r = re.compile(r'<a href="(http://[^ ]+)">(http://[^ ]+)</a>')
print r.sub(r'\1', myString)

Should work.