string interpolation mystery in Python 2.6

Fri Sep 11 18:12:22 EDT 2009

Michael Foord came up with a much simpler
illustration. With Python 2.6::
 >>> try:
 ... open('flooble')
 ... except Exception as e:
 ... pass
 ...
 >>> e
 IOError(2, 'No such file or directory')
 >>> unicode(e)
 u"(2, 'No such file or directory')"
 >>> str(e)
 "[Errno 2] No such file or directory: 'flooble'"
 >>> u'%s' % e
 u"(2, 'No such file or directory')"
 >>> '%s' % e
 "[Errno 2] No such file or directory: 'flooble'"
Cheers,
Alan Isaac