June 9, 2003
7:26 p.m.
Quoth Guido van Rossum: [...]
Python usually doesn't care about isinstance relationships but cares about whether the needed protocol is implemented, and this suggests that requiring exceptions to subclass Exception is unPythonic.
[Steven T]
This came up in python-list not long ago [1], and I raised (heh) exactly that argument. Alex Martelli counterargued that exceptions are one area in which we *do* usually care about isinstance relationships, since that's how we specify which exceptions to catch.
[1] http://mail.python.org/pipermail/python-list/2003-May/160965.html
Excellent argument. Thanks, Steve and Alex. --Guido van Rossum (home page: http://www.python.org/~guido/)