[Python-ideas] except expression

[Ron Adam]

On 02/19/2014 08:58 PM, Greg Ewing wrote:
> Another idea:
>
>     things[i] or else None if IndexError
>
> You can't claim that the exception is in the wrong place
> in relation to the 'except' keyword, because there is no
> 'except' keyword!


By adding a __bool__ attribue to exceptions that always returns False, you 
can get some of that, but it has the same issues that logic operators have 
when a normally False item is also valid data.

To get around that we would need a differently based logic system where the 
caught exception(s) are the only False values.

Exception logic with False as an exception.

     e1 and e2 or e3

Translate to this...

     try:
         e1
         e2
     except False:
         e3


Then with IndexError.

     (except IndexError: things[i] or None)


Cheers,
    Ron