Dan Esch wrote: > Wait a sec... > > I think I get this... > > In essence, the implication of immutability for Python is that there is > only one "parrot", one "spam,"in fact one anything. (This seems like it > must hold for data primitives - does it hold for complex objects as > well? It seems it must...) In addition there is only one 1, and one 2 > etc. We may or may not have realized that string in a memory address to > which variable names can be bound, but should we do so, there is only > one "parrot" > > Python, is in fact, a Platonic programming language. Weird. If I've > got this right, worth chewing on.... > 'Fraid not. Certain immutables are cached by the interpreter, but most are not.
>>> s1 = "a" + "b" + "c" >>> n = 12345 >>> s2 = "ab" + chr(99) >>> m = 2469 * 5 >>> s1 == s2 True >>> s1 is s2 False >>> n == m True >>> n is m False >>> id(s1), id(s2), id(n), id(m) (2146661888, 2146661792, 14453620, 14453584) >>> regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
