>>> s=[1,2,3] >>> s.append(5) >>> s [1, 2, 3, 5] >>> s=s.append(5) >>> s >>> print s None why can't s=s.append(5) ,what is the reason? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-list/attachments/20120523/2e1720ff/attachment.html>