Is my thinking Pythonic?

[Diez B. Roggisch]

Craig Allen wrote:

> generally, I name the members in the Class definition and set them to
> None there...
> 
> class Car:
>    speed = None
>    brand = None
> 
>    def __init__():
>       self.speed = defaultspeed #alternately, and more commonly, get
> this speed as a initializer argument
>       self.brand = defaultbrand
> 
> 
> That solves the issue of being able to "see" all the members of an
> object by reading code... however, this all goes out the window when
> composing an instance dynamically (i.e. metaclass type stuff).

While I use this idiom myself, one must be cautious not to create unwanted
side-effects if anything mutable comes into play:

class Foo:
   bar = []
 
   def baz(self):
       self.bar.append(2)


will *not* make bar instance-variable, but keep it as class-variable.