Why no warnings when re-assigning builtin names?
Terry Reedy
tjreedy at udel.edu
Tue Aug 16 22:10:30 EDT 2011
On 8/16/2011 7:49 PM, Seebs wrote:
> On 2011-08-16, Terry Reedy<tjreedy at udel.edu> wrote:
>> On 8/16/2011 2:56 PM, Seebs wrote:
>>> I wonder whether there's a way to mitigate the cost of these things by
>>> messing with -W settings, such that runtime that wants to be fast can
>>> omit the checks, but the default could still be to, well, prevent likely
>>> errors.
>
>> Warning messages have a cost even if suppressed.
>
> Yes, but is it a *significant* cost? My assumption is that the suppression
> would be of checking, not just of displaying messages.
The -W settings suppress display or printing of warnings, not their
generation.
import warnings
if some_condition:
warnings.warn(message, Warning)
The test and warn call are made regardless of disposition. Filters
determine what is done with each Warning subclass. The logging module
can grab them too.
--
Terry Jan Reedy
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