On Wed, 17 Dec 2008 15:19:32 -0000, walterbyrd <walterb...@iname.com>
wrote:
However in the methods are within a class, the scoping seems to work
differently.
Not really. Hopefully this commentary will show you why.
class ab():
def a(self):
self.x = 99
print self.x
def b(self):
print self.x
i = ab()
This creates |i|, an instance of class |ab|. As yet it is pure and
virgin, having nothing but the methods that it gets from |ab|. Soon this
will change...
i.a()
This creates an attribute |x| in |i|, and assigns the number 99 to it.
i.b() # this works, why no lexical scoping?
This works because you ran |i.a()| first, so |i.x| exists and can be
printed out. Lexical scoping is going on here, you're just mistaking
what's being scoped; it's the |self| in |b|, which is in scope because
it's a parameter. This particular |self| (the |i| you made earlier)
happens to have an attribute |x|, so it all works. If however you'd
written:
j = ab()
j.b()
then Python would whinge mightily at you, claiming that it knoweth naught
of this |x| attribute of which you speak, and can it go home now for this
is a silly place. The |self| in |b| is still in lexical scope, though.
--
Rhodri James *-* Wildebeeste Herder to the Masses
--
http://mail.python.org/mailman/listinfo/python-list
