New submission from Nick Coghlan <ncogh...@gmail.com>: This proposal is an outcome of repeated requests on python-ideas that assert statements be made unconditional, so they can be legitimately used for parameter validation, rather than solely as a form of inline self-test.
Rather than changing the assert statement, an alternative option would be to provide a new builtin (suggested name: "ensure") that raises ValidationError (a new subclass of AssertionError) if the first argument is false. As a function, the new builtin could accept parameters for: - the message to be reported on failure - the exception type to be raised on failure And since it would only be a new builtin rather than a new keyword, existing uses of the name "ensure" would be unaffected (except to the extent that linters may start warning about shadowing a builtin). (Since it's a suggestion for a new builtin, actually doing this would require a PEP, which I'm not planning to write, I just wanted to get the suggestion explicitly on the record rather than leaving it buried in mailing list archives) ---------- messages: 310219 nosy: ncoghlan priority: normal severity: normal stage: needs patch status: open title: Proposal: add an "ensure(arg)" builtin for parameter validation type: enhancement _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue32590> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
