> > I was just at a point when I thought I learned something but got > > confused again after trying the following and unfortunately didn't > > find an answer in the docs. > > > >>>> a = 10 > >>>> b = 10 > >>>> id(a) > > 134536516 > >>>> id(b) > > 134536516 > > > > So the two memory addesses are the same, but > > > >>>> a = 10000 > >>>> b = 10000 > >>>> id(a) > > 134604216 > >>>> id(b) > > 134604252 > > > > and they are not the same (I restarted the interpreter between the two > > cases). So how is this now? Sorry if it's too trivial, but I simply > > don't get it. > > It's an optimization scheme that will cache number objects up to a certain > value for optimized reuse. However this is impractical for larger numbers - > you only hold a table of lets say 1000 or so objects. Then the look up of > one of those objects is extremely fast, whereas the construction of > arbitrary numbers is somewhat more expensive. > > And as "is" is the operator for testing if objects are identical and _not_ > the operator for testing of equality (which is ==), the above can happen. > And is totally irrelevant from a practical POV (coding-wise that is - it > _is_ a relevant optimization).
Thanks a lot! So after all I really learned something :) -- http://mail.python.org/mailman/listinfo/python-list
