To be more specific, if the last `elif` condition permits all remaining permissible conditions (which I suppose would just be whatever is asserted by the proposed syntax), then the else block can just be the raising of the exception.
On Thu, Jul 2, 2020, 7:52 PM Steele Farnsworth email@example.com wrote:
Assertions aren't guaranteed to be executed and thus should never be used where raising an error is required.
`else: raise SomeError('reason')` already has the desired effect, and it's plenty readable.
On Thu, Jul 2, 2020, 7:46 PM Artemis firstname.lastname@example.org wrote:
Often, I know that a variable should have one of a set of values, and I want to determine which one, with an if/elif/else clause. This looks something like this:
if foo == 1: # do a elif foo == 2: # do b elif foo == 3: # do c else: raise ValueError('foo must be 1, 2 or 3')
Sometimes, I just do
if foo == 1: # do a elif foo == 2: # do b else: # do c
But this is less readable and allows errors to slip past. My proposal is to allow the following syntax:
if foo == 1: # do a elif foo == 2: # do b else foo == 3: # do c
Or perhaps the more readable version:
if foo == 1: # do a elif foo == 2: # do b else assert foo == 3: # do c
Both of these options are backward compatible, since currently nothing is allowed between the `else` and the `:`. This would be roughly equivalent to
if foo == 1: # do a elif foo == 2: # do b else: assert foo == 3 # do c
But shorter and more readable, since it puts the assertion at the same levels as the others. Thoughts? _______________________________________________ Python-ideas mailing list -- email@example.com To unsubscribe send an email to firstname.lastname@example.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://email@example.com/message/ZKAQK7... Code of Conduct: http://python.org/psf/codeofconduct/