Re: [pygame] Concerning copy

[James Paige <Bob@xxxxxxxxxxxxxxxxxxx>]

On Wed, Apr 26, 2006 at 08:54:07PM -0700, Kamilche wrote:
> Nate Nichols wrote:
> >In my limited experience with Python/PyGame, it seems to me like list
> >comprehensions are a good way around this "bug".
> >
> >Instead of
> >
> >def main():
> >    nums = [x for x in range(10)]
> >    for num in nums:
> >         if num % 2 = 0:
> >               nums.remove(num)
> >
> 
> That's not good. It's misleading the programmer into thinking 
> divisibility by 2 is an important criterion. What if it was a list of 
> objects instead of numbers, and not divisible at all?
> 
> It's better to either copy the list as in the following code:
> 
> def main():
>     nums = [x for x in range(10)]
>     print nums
>     for num in nums[:]:
>         nums.remove(num)
>     print nums
> main()
> 
> or iterate over its length like this:
> 
> def main():
>     nums = [x for x in range(10)]
>     print nums
>     for i in range(len(nums)):
>         del nums[0]
>     print nums
> main()

Why make things this complicated?

  nums = [x for x in range(10)]
  del nums

That is all you need to do. And if you are working with objects that 
need to be "cleaned up", just put the cleanup code in __del__()

Are you perhaps trying to delete members of a list of objects with known 
circular depenencies that prevent them from being deleted in the normal 
simple way?

---
James Paige