class variable won't icrement!
thomas at xs4all.net
Thu Sep 12 09:44:25 EDT 2002
On Thu, Sep 12, 2002 at 09:14:22AM -0400, Jp Calderone wrote:
> On Thu, Sep 12, 2002 at 12:18:32PM +0200, Roman Yakovenko wrote:
> > Hi it is simple just change
> > self.id = self.id + 1
> > To
> > test.id += 1
> Actually, that turns out not to be the case. += behaves differently
> depending on its arguments - sometimes rebinding the name, sometimes
> mutating in place. For integers, it can not mutate in place (ints are
> immutable, of course!) so "self.id = self.id + 1" is exactly the same as
> "self.id += 1". Were 'id' a mutable type, say a list, then the above
> solution would work (assuming you changed 1 to something iterable).
Notice how Ramon said 'test.id', not 'self.id. He's changing the class
attribute directly, not through the instance. The switch from
addition+assignment to augmented assignment is just a smoke screen :)
Thomas Wouters <thomas at xs4all.net>
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