On Fri, May 21, 2010 at 11:49 AM, Chris Rebert <c...@rebertia.com> wrote: > On Fri, May 21, 2010 at 11:38 AM, Alex Hall <mehg...@gmail.com> wrote: >> On 5/21/10, Christian Heimes <li...@cheimes.de> wrote: >>> Am 21.05.2010 04:56, schrieb Alex Hall: >>>> Hi all, >>>> I am now trying to allow my classes, all of which subclass a single >>>> class (if that is the term), to provide optional arguments. Here is >>>> some of my code: >>>> >>>> class Craft(): >>>> def __init__(self, >>>> name, >>>> isAircraft=False, >>>> id=helpers.id(), >>>> hits=0, >>>> weapons=[]): >>> >>> I hope you are aware that helpers.id() is called just once when the >>> *class* is defined and that the list weapons is shared across all >>> instances of the craft class. :) >> I know id is called once, but what do you mean weapons is shared? > > Read the "Important warning" on > http://docs.python.org/tutorial/controlflow.html#default-argument-values > `weapons` will be the *exact same list object* for all Craft instances > the way you have it currently (i.e. it will not be copied and changes > to it will affect all Crafts).
Er, all Craft instances /where you didn't pass an explicit `weapons` argument to the constructor/, that is. - Chris -- http://mail.python.org/mailman/listinfo/python-list
