Safari Books Online is a digital library providing on-demand subscription access to thousands of learning resources.
- Create BookmarkCreate Bookmark
- Create Note or TagCreate Note or Tag
- DownloadDownload
- PrintPrint
VII. Exceptions and Tools > 34. Exception Objects
So far, I’ve been deliberately vague about what an exception actually is. As suggested in the prior chapter, in Python 2.6 and 3.0 both built-in and user-defined exceptions are identified by class instance objects. Although this means you must use object-oriented programming to define new exceptions in your programs, classes and OOP in general offer a number of benefits.
Here are some of the advantages of class-based exceptions:
-
They can be organized into categories. Exception classes support future changes by providing categories—adding new exceptions in the future won’t generally require changes in
trystatements. -
They have attached state information. Exception classes provide a natural place for us to store context information for use in the
tryhandler—they may have both attached state information and callable methods, accessible through instances.
