Will python never intend to support private, protected and public?

[Paul Rubin]

"El Pitonero" <pitonero at gmail.com> writes:
> The thing is, there are two sides to every coin. Features surely can
> be viewed as "goodies", or they can be viewed as "handcuffs".

Let's see, say I'm a bank manager, and I want to close my cash vault
at 5pm today and set its time lock so it can't be opened until 9am
tomorrow, including by me.  Is that "handcuffs"?  It's normal
procedure at any bank, for good reason.  It's not necessarily some
distrustful policy that the bank CEO set to keep me from robbing the
bank.  I might have set the policy myself.  Java lets me do something
similar with instance variables.  Why is it somehow an advantage for
Python to withhold such a capability?

> Sure, in these very dynamic languages you can ACCIDENTALLY override
> the default system behavior. How many Python programmers have once
> upon a time done stupid things like:
> list = 3

That's just a peculiarity, not any deep aspect of Python.  Try it for
'None' instead of 'list':

    >>> None = 3
    SyntaxError: assignment to None

Why is 'list' somehow different from 'None'?  I'd say there's a case
to be made for having the compiler protect 'list' and other builtins
the same way it protects 'None'.  Python won't be any less dynamic
because of it.

> The upside is exactly the same as the fact that you can override the
> "list()" function in Python.  Python is dynamic language. 

That's not exactly an upside, and it has nothing to do with Python
being dynamic.  C is static but you can override 'printf'.  Overriding
'list' in Python is pretty much the same thing.

> In Python, if you have a private variable:
> 
> self._x = 3
> 
> and you, for curiosity reasons and DURING runtime (after the program is
> already up and running) want to know the exact moment the self._x
> variable is accessed (say, print out the local time), or print out the
> calling stack frames, you can do it. And I mean the program is running.

So let's see:

  def countdown():
    n = 3
    while n > 0:
       yield n
  g = countdown()
  print g.next()  # 3
  print g.next()  # 2

where's the Python feature that lets me modify g's internal value of n
at this point?  How is that different from modifying a private
instance variable?  "Python feature" means something in the language
definition, not an artifact of some particular implementation.  Is
Python somehow deficient because it doesn't give a way to do that?  Do
you want to write a PEP to add a way?  Do you think anyone will take
it seriously?

[Other stuff incomprehensible and snipped].