Like urlize, but truncates the link text to n characters.
Converts URLs in a string to clickable links by wrapping them in an <a> tag. It identifies URLs that begin with http://, https://, or www. It also converts syntactically valid email addresses.
Variable
html = '''Check out our Python training at www.webucator.com/programming-training/python-training.cfm. If you have any questions, email [email protected].'''
Template
{{ html|urlizetrunc:25 }}
Result
Check out our Python training at <a href="http://www.webucator.com/programming-training/python-training.cfm" rel="nofollow">www.webucator.…</a>. If you have any questions, email <a href="mailto:[email protected]">sales@webucato…</a>.
The generated links will be nofollow links.
Warning
According to the official documentation, this filter does not play nice with text already marked up as HTML.

Commentary
Like
urlize, this would be more useful if it could be applied safely to text already marked up as HTML. Also, the truncated URLs can be just plain ugly.