markup = '<a href="http://example.com/">I linked to <i>example.com</i></a>'

soup = BeautifulSoup(markup)

tag = soup.a

​

tag.insert(1, "but did not endorse ")

tag

# <a href="http://example.com/">I linked to but did not endorse <i>example.com</i></a>

tag.contents

# [u'I linked to ', u'but did not endorse', <i>example.com</i>]