Unclear On Class Variables

[Antoon Pardon]

>
> Well I find this a confusing behaviour on python's part. The fact
> that instance.field can mean something different, depending on
> where in a statement you find it, makes the behaviour inconsistent.
>
> I know people in general here are against declarations, but declarations
> could IMO provide more consistency here and thus more obvious behaviour.

Well just to show how confusing python can be, the following piece of
code.

| class Spam:
|   eggs = [2, 3]
| 
| 
| sp1 = Spam()
| sp2 = Spam()
| 
| print sp1.eggs, id(sp1.eggs)
| print sp2.eggs, id(sp2.eggs)
| print '--------------------'
| 
| sp1.eggs += [4,]
|
| print sp1.eggs, id(sp1.eggs)
| print sp2.eggs, id(sp2.eggs)
| print '--------------------'
|
| Spam.eggs = [3,5]
|
| print sp1.eggs, id(sp1.eggs)
| print sp2.eggs, id(sp2.eggs)
| print '--------------------'

Which produces:

[2, 3] 1075958860
[2, 3] 1075958860
--------------------
[2, 3, 4] 1075958860
[2, 3, 4] 1075958860
--------------------
[2, 3, 4] 1075958860
[3, 5] 1075959084
--------------------