Removing objects

[Asun Friere]

On Jan 23, 5:59 pm, bladedpeng... at gmail.com wrote:
> I am writing a game, and it must keep a list of objects. I've been
> representing this as a list, but I need an object to be able to remove
> itself. It doesn't know it's own index. If I tried to make each object
> keep track of it's own index, it would be invalidated when any object
> with a lower index was deleted.  The error was that when I called
> list.remove(self), it just removed the first thing in hte list with
> the same type as what I wanted, rather than the object I wanted. The
> objects have no identifying charachteristics, other than thier
> location in memory
>
> So my question: How do I look something up in a list by it's location
> in memory? does python even support pointers?
>
> Is there a better way?


How about adding an id attribute to your objects, which will contain a
unique identifier, override __eq__ to use that id to compare itself to
others and then simply pop off the object using
object_list.pop(object_list.index(self)).  Something like this:

>>> class Spam (object) :
	def __init__ (self, id) :
		self.id = id
	def __eq__ (self, other) :
		try :
			return self.id == other.id
		except AttributeError :
			return False


>>>
>>> a,b,c = Spam(1), Spam(2), Spam(3)
>>> x = [a,b,c]
>>> x.pop(x.index(c))
<__main__.Spam object at 0x885e5ac>

Except your object would be telling the list to pop self of course,
and you'd need someway of insuring the uniqueness of your IDs.