object identity and hashing

castironpi at gmail.com castironpi at gmail.com
Wed Feb 27 13:35:42 CET 2008


On Feb 25, 7:44 pm, Jeff Schwab <j... at schwabcenter.com> wrote:
> castiro... at gmail.com wrote:
> > On Feb 24, 9:28 pm, George Sakkis <george.sak... at gmail.com> wrote:
>
> >> [1]http://www.martinfowler.com/eaaCatalog/identityMap.html
>
> > [1] illustrates a case in which 'a is a' returns False, and in the
> > other corner of the DeMorgan table, there is 'a is b' returns True for
> > 'a == b' False.
>
> What is the 'a is a' == False case?  I don't see anything like that
> illustrated on the Identity Map page.  Is it "P of EAA?"

Good point.  I don't know.  Just another logical possibility to go in
the 1% of cases.  What is P of EAA?

Also, notice: For the list and tuple types, x in y is true if and only
if there exists an index i such that x == y[i] is true-- from the
docs.

And:>>> 'abc' is 'abc'
True




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