extending objects (object-specific subclassing)

[David Garamond]

in ruby you can "subclass an object". that is, you override and/or add 
methods specific to an object, not for the entire class. an example below:

  a = "hello"
  b = a.dup # b becomes another String object with the value of "hello"

  def b.to_s
    "The value is '#{self}'"
  end

  puts a.to_s # hello
  puts b.to_s # The value is 'hello'

behind the scene, ruby creates a new class just for the object a. the 
original a's class, String, will be the new class' superclass. ruby 
hides this, though, so you'll still see a as being the String object.

  puts a.class # String
  puts b.class # String

i wonder if python has a similar concept. or how do we do something 
roughly similar in python.

-- 
dave