PEP 3107 and stronger typing (note: probably a newbie question)

[Ben Finney]

Stephen R Laniel <steve at laniels.org> writes:

> Perhaps it would help for me to explain what I'd like.

Thanks for taking the time to think about the request and re-formulate
it.

> Under both Perl and Python, I've found myself
> having/wanting to write things like so:
>
> def my_func( int_arg, str_arg ):
>     try:
>         int_arg = int( int_arg )
>         str_arg = str( str_arg )
>     except ValueError:
>         sys.stderr.write( "Args are not of the right type\n" )
>         sys.exit(1)

The first question that comes to mind -- and you'll find this question
asked of hundreds of people who come to this list with similar stated
goals -- is this: Why are you doing the above?

In Python, the pattern is to allow that exception to propagate back to
the code that tried to use the function, which is the one that is
apparently using the function incorrectly.

That is, you haven't actually told us what you'd like. You've shown us
a function that effectively does nothing but create a str and and int
-- and then discard them. What does this function need to do that you
want to catch an exception and abort inside the function?

-- 
 \          "It is well to remember that the entire universe, with one |
  `\       trifling exception, is composed of others."  -- John Andrew |
_o__)                                                           Holmes |
Ben Finney