id == vs is

Roy Smith roy at
Mon Oct 27 14:17:34 CET 2014

In article <mailman.15221.1414379336.18130.python-list at>,
 Cameron Simpson <cs at> wrote:

> The "is" test is more direct and less subject to iffiness because the longer 
> expression using id() leaves more scope/time for things to change, and of 
> course "id" itself can be rebound to something weird.

Not to mention that Python is case-sensitive and in the code as 
presented by the OP:

>>>>Id(x) == id(y)

those are two different functions :-)

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