[Python-Dev] Issue #26204: compiler now emits a SyntaxWarning on constant statement (original) (raw)

Yury Selivanov yselivanov.ml at gmail.com
Tue Feb 9 17:15:47 EST 2016

On 2016-02-08 8:02 PM, Steven D'Aprano wrote:

On Mon, Feb 08, 2016 at 05:43:25PM -0500, Yury Selivanov wrote:

On 2016-02-08 5:19 PM, Terry Reedy wrote: On 2/8/2016 4:51 PM, Victor Stinner wrote: 2016-02-08 22:28 GMT+01:00 Alexander Walters <tritium-list at sdamon.com>:

What incantation do you need to do to make that behavior apparent? I didn't know. I just checked. It's assert used with a non-empty tuple:

assert ("tuple",) :1: SyntaxWarning: assertion is always true, perhaps remove parentheses? I think this should be left to linters also. I agree. I'd remove that warning. Please don't remove the warning, it is very useful. Compare an assertion written correctly: py> assert 1==2, "Error in arithmetic" Traceback (most recent call last): File "", line 1, in AssertionError: Error in arithmetic with the simple mistake of wrapping the "tuple" in parens: py> assert (1==2, "Error in arithmetic") :1: SyntaxWarning: assertion is always true, perhaps remove parentheses? py>

You're right! It's indeed a trap that we should warn about.

Thanks!

Yury

More information about the Python-Dev mailing list