[Python-ideas] Make "is" checks on non-singleton literals errors

Guido van Rossum guido at python.org
Tue Oct 9 00:26:57 CEST 2012

On Mon, Oct 8, 2012 at 3:02 PM, Chris Angelico <rosuav at gmail.com> wrote:
> On Tue, Oct 9, 2012 at 6:44 AM, Mike Graham <mikegraham at gmail.com> wrote:
>> There are no cases where
>>     if x is "foo":
>> is actually the code someone intended to write.
> Are literals guaranteed to be interned? If so, this code would make
> sense, if the programmer knows that x is itself an interned string.

No, interning is not guaranteed.

> Although I guess a warning wouldn't be a problem there, as they're
> easily ignored/suppressed.

--Guido van Rossum (python.org/~guido)

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