On 12/03/2021 4:31 pm, Chris Angelico wrote:
On Fri, Mar 12, 2021 at 3:53 PM Cameron Simpson <c...@cskk.id.au> wrote:For me, try/except is for when something might reasonably "go wrong" in normal use, even niche normal use. Whereas assert is for things which should _never_ occur. Roughly, again for me, try/except if for catching misuse and assert is for catching misdesign/misimplementation.Something like that, yeah. An assertion failure represents a bug *in this code*, something that shouldn't ever happen. If it's possible to trigger the failure with some other piece of code (calling something with bad arguments, or whatever), then assert is the wrong tool for the job. Similarly, if you find yourself catching AssertionError anywhere outside of unit testing, something is horribly wrong somewhere :)
I haven't been following this thread so please forgive me if this has been said ...
My understanding of the reason for assert is to support the "design by contract" programming style of Eiffel as espoused by Bertrand Meyer. I don't suppose it makes much difference whether it is a function or a callable for that - and when I first saw it I was appropriately confused - but I only ever used it when I was absolutely certain the assertion was bullet-proof. And it is a long time since I did that. I prefer try-except nowadays.
Mike
ChrisA
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