custom exceptions in python

custom_exceptions.py

In [1]: def raise_exception():
   ...:     raise Exception('the base exception')
   ...:
 
In [2]: try:
   ...:     raise_exception()
   ...: except Exception, e:
   ...:     print "caught: %s" % e
   ...:     
caught: the base exception

In [3]: class CustomException(Exception):
   ...:     pass
   ...: 

In [4]: try:
   ...:     raise CustomException('a custom exception')
   ...: except CustomException, e:
   ...:     print "caught: %s" % e
   ...:     
caught: a custom exception