\begin{verbatim}
>>> ('http://www.python.org').partition('://')
('http', '://', 'www.python.org')
->>> (u'Subject: a quick question').partition(':')
-(u'Subject', u':', u' a quick question')
>>> ('file:/usr/share/doc/index.html').partition('://')
('file:/usr/share/doc/index.html', '', '')
+>>> (u'Subject: a quick question').partition(':')
+(u'Subject', u':', u' a quick question')
>>> 'www.python.org'.rpartition('.')
('www.python', '.', 'org')
+>>> 'www.python.org'.rpartition(':')
+('', '', 'www.python.org')
\end{verbatim}
(Implemented by Fredrik Lundh following a suggestion by Raymond Hettinger.)