So uh, this is a hardly at all fleshed out idea, but one thing we really don't like about python is having to do stuff like this so as to not swallow exceptions:
def a_potentially_recursive_function(some, args): """ Does stuff and things. Raises ExceptionWeCareAbout under so and so conditions. """ try: some.user_code() except ExceptionWeCareAbout as exc: raise RuntimeError from exc code_we_assume_is_safe() if args.something and some_condition: raise ExceptionWeCareAbout It'd be nice if there was a way to... make this easier to deal with. Perhaps something where, something like this: def a_potentially_recursive_function(some, args) with ExceptionWeCareAbout: """ Does stuff and things. Raises ExceptionWeCareAbout under so and so conditions. """ some.user_code() code_we_assume_is_safe() if args.something and some_condition: raise ExceptionWeCareAbout becomes: def a_potentially_recursive_function(some, args): """ Does stuff and things. Raises ExceptionWeCareAbout under so and so conditions. """ try: some.user_code() code_we_assume_is_safe() if args.something and some_condition: let_exception_through = True raise ExceptionWeCareAbout except ExceptionWeCareAbout as exc: if let_exception_through: raise else: raise RuntimeError from exc (or equivalent) and something like: def foo() with Bar: try: baz() except Bar: raise becomes: def foo(): try: try: baz() except Bar: allow_exception = True raise except Bar as exc: if allow_exception: raise else: raise RuntimeError from exc (thus allowing explicit exception propagation) Additionally, note that it would only apply to the raise itself - something like `raise may_raise_the_same_error()` would desugar as if: exception = may_raise_the_same_error() allow_exception = True raise exception Obviously this doesn't solve exception handling, doesn't require the caller to catch the exceptions, etc etc. It does, however, encourage better exception hygiene. Chances are something like this would significantly reduce the amount of swallowed exceptions, if it gets widely adopted. We know something like this would've saved us a lot of trouble, so we're sharing the idea in the hopes it can, in the future, help others. _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/TGHIGKWEHKS4MEDMDFMHS3FBAHENLTUB/ Code of Conduct: http://python.org/psf/codeofconduct/
