Question: processing HTML, re-write default processing action of many tags

[Hubert Hung-Hsien Chang]

I know you could use the 


def start_a
....

def end_a
....

to process the <a href=...> anchor </a> tags, but is there a 
default method for processing ALL tags? If I just want change 
some parts of the hyperlink and want to keep other parts of the HTML
could I just print them out? There should be such a method.
Can't find it...

Thank you.