Python Exceptions >>> raise

A neat trick i found in the python tutorial:

If you need to determine whether an exception was raised but don't intend to handle it, a simpler form of the raise statement allows you to re-raise the exception:

>>> try:
...     raise NameError, 'HiThere'
... except NameError:
...     print 'An exception flew by!'
...     raise
...
An exception flew by!
Traceback (most recent call last):
 File "", line 2, in ?
NameError: HiThere

For more read the Errors and Exceptions section