Which exception to use?

[Peter Hansen]

"Edward C. Jones" wrote:
> 
> Which exception is it best to use in the following pieces of code?
> 
> if len(sys.argv) != 2:
>      raise SomeException, 'program requires exactly one argument'
> 
> if len(sometuple) != 3:
>      raise SomeException, 'sometuple must have length 3'
> 
> I use TypeError or ValueError but they don't feel right. I wish there
> was a SizeError or LengthError.

IndexError?  If you wish to use that, you don't even need to
do the test yourself. ;-)

By the way, I believe "raise SomeException('program blah blah')" is
the more correct way of expressing the above.

-=Peter