On 3/25/06, David Isaac <[EMAIL PROTECTED]> wrote: > "Ziga Seilnacht" <[EMAIL PROTECTED]> wrote in message > news:[EMAIL PROTECTED] > > >>> a = 10000 > > >>> b = 10000 > > >>> a == b > > True > > >>> a is b > > False > > Two follow up questions: > > 1. I wondered about your example, > and noticed > >>> a = 10 > >>> b = 10 > >>> a is b > True > > Why the difference? > > 2. If I really want a value True will I ever go astray with the test: > if a is True: > >>> a = True > >>> b = 1. > >>> c = 1 > >>> a is True, b is True, c is True > (True, False, False) >
None, True, and False are all singletons and should be compared with "is". There are some other singletons - small integers (up to 10, I believe) as well as the empty string. However, I am not sure (and I am sure someone will correct me if I'm wrong) but I believe that these are not specified as singletons, and that it's an implementation detail that they are. > Thanks, > Alan Isaac > > > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
