Name mangling

[Fredrik Lundh]

ullrich at math.okstate.edu wrote:
> > section 9.6 in the tutorial discusses this:
> >
> >     http://www.python.org/doc/current/tut/node11.html
> >
> >     "Any identifier of the form __spam (at least two
> >     leading underscores, at most one trailing under-
> >     score) is now textually replaced with
> >     _classname__spam, where classname is the
> >     current class name with leading underscore(s)
> >     stripped. This mangling is done without regard
> >     of the syntactic position of the identifier, so it
> >     can be used to define class-private instance
> >     and class variables, methods, as well as globals,
> >     and even to store instance variables private to
> >     this class on instances of other classes"
>
>     Thanks. But actually I'd found that part in the docs,
> but I don't see how it implies that the silly snippet I
> posted should not work. Probably I'm just being dense,
> but usually when I find the right page in the docs I get
> an "aha" out of it - here I don't get it at all...

oh, I forgot to include the important part: the paragraph
I quoted ends with this sentence:

    "Outside classes, or when the class name consists
    of only underscores, no mangling occurs."

in other words, this works:

_C__foo = 42

class C:
  def __init__(self):
    self.value = __foo

c = C()

</F>