Result of ``a is b''

[Andrew Koenig]

"Axel Boldt" <axelboldt at yahoo.com> wrote in message
news:40200384.0403151632.35496ee6 at posting.google.com...

> is there a rationale for the following behavior:
>
>   >>> a = (1,2)
>   >>> b = (1,2)
>   >>> a is b
>   False
>   >>> a = "12"
>   >>> b = "12"
>   >>> a is b
>   True

Probably an accident of implementation.  Consider:

>>> a = "1 2"
>>> b = "1" + " 2"
>>> a is b
False

and, for that matter:

>>> a = (1, 2)
>>> b = a
>>> a is b
True

Is there a reason that you care about this behavior?