On Aug 29, 8:08 am, Paul McGuire <pt...@austin.rr.com> wrote: > On Aug 29, 7:45 am, zaur <szp...@gmail.com> wrote: > > > Python 2.6.2 (r262:71600, Apr 16 2009, 09:17:39) > > [GCC 4.0.1 (Apple Computer, Inc. build 5250)] on darwin > > Type "copyright", "credits" or "license()" for more information.>>> a=1 > > >>> x=[a] > > >>> id(a)==id(x[0]) > > True > > >>> a+=1 > > >>> a > > 2 > > >>> x[0] > > > 1 > > > I thought that += should only change the value of the int object. But > > += create new. > > Is this intentional? > > ints are immutable. But your logic works fine with a mutable object, > like a list:
Technically, mutability isn't the issue: There's nothing enforcing that a mutable object HAS to have an __iadd__ method that returns the same object. -- http://mail.python.org/mailman/listinfo/python-list
