On 2017-11-28 04:27 PM, Ivan Pozdeev via Python-ideas wrote:
On 28.11.2017 20:23, Ethan Furman wrote
On 11/28/2017 08:03 AM, Ivan Pozdeev via Python-ideas wrote:
On 28.11.2017 16:36, Nick Coghlan wrote:
it doesn't need to be a statement any more
Another benefit of a statement vs function is only evaluating the error-related arguments when there's an error
The bulk of any processing in assert (or ensure()) should be the actual check -- if that fails, only state information should be included in the exception as anything more complicated runs the risk of also being wrong as the code is now in a failed state. In other words, the "error-related arguments" will often be extremely cheap compared to the test itself.
My experience is the contrary. The check is usually trivial -- a type check or comparison. While a useful error message contains problem details, so it incorporates string formatting from a variable or two or expressions thereof, like "expected <type>, got <type(var)>".
ensure(check, lambda: raise TypeError("expected <type>, got <type(var)>"))?
-- ~Ethan~ _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/