Difference between 'is' and '=='

Joel Hedlund joel.hedlund at gmail.com
Wed Mar 29 09:44:44 CEST 2006

> If it weren't for the current CPython optimization (caching small 
> integers) 

This has already been covered elsewhere in this thread. Read up on it.

> this code which it appears you would support writing
>    if (flags & os.R_OK) is os.R_OK:

I do not.

You compare a module.CONSTANT to the result of an expression (flags & os.R_OK). 
Expressions are not names bound to objects, the identity of which is what I'm 
talking about. This example does not apply. Also, the identity check in my 
example has a value equality fallback. Yours doesn't, so it really does not apply.

 > (I think you should give it up... you're trying to push a rope.)

I'm not pushing anything. I just don't like being misquoted.

Joel Hedlund

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