Over my head with descriptors

[Tim Roberts]

"Sarcastic Zombie" <sarcasticzombie at gmail.com> wrote:
>
>Code included below.
>
>Basically, I've created a series of "question" descriptors, which each
>hold a managed value. This is so I can implement validation, and render
>each field into html automatically for forms.
>
>My problem is this: every instance of my "wizard" class has unique self
>values, but they share the exact same descriptor values.
>
>...
>class Test(Wizard):
>	grouping = [
>		[ 'age', 'weight' ],
>		[ 'feet', 'inches' ],
>		['name', 'cash', 'fav_color', 'happy', 'birthday'] ]
>
>	def __new__(self):
>		age = Q_Integer("Your Age:", "age", 99)
>		weight = Q_Integer("Your Weight:", "weight", 200)
>		feet = Q_Integer("Feet tall:", "feet", 6)
>		inches = Q_Integer("Inches Tall:", "inches", 0)
>		name = Q_Chars("Your Name:", "name", max_length=15, required=True)
>		cash = Q_Float("Money in hand?", "cash", required=True,
>default=55.50)
>		fav_color = Q_Chars("Your favorite color?", "fav_color",
>required=True, max_length=50, choices=C_CHOICES)
>		homezip = Q_Zip("Your zip code?", "homezip", required=True, )
>		happy = Q_Bool("Are you happy?", "happy", default=False)
>		birthday = Q_Date("Your Birthday:", "birthday")

The __new__ method is called with the CLASS as its first argument, not the
new instance.  __new__ is supposed to RETURN the new instance.  So, when
you set "age", you are setting a CLASS attribute that will be shared by all
instances.

Is there a reason you don't just use __init__ instead of __new__, and use
"self.age" and "self.weight" and so on?
-- 
Tim Roberts, timr at probo.com
Providenza & Boekelheide, Inc.