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Re: Nice solution wanted: Hide internal interfaces

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Johannes Bauer wrote:

> Now I want A to call some private methods of B and vice versa (i.e. what
> C++ "friends" are), but I want to make it hard for the user to call
> these private methods.
> 
> Currently my ugly approach is this: I delare the internal methods
> private (hide from user). Then I have a function which gives me a
> dictionary of callbacks to the private functions of the other objects.
> This is in my opinion pretty ugly (but it works and does what I want).
> 
> I'm pretty damn sure there's a nicer (prettier) solution out there, but
> I can't currently think of it. Do you have any hints?

Maybe you  can wrap A into a class that delegates to A:

>>> class A(object):
...     def __private(self): print "private A"
... 
>>> class Friend(object):
...     def __init__(self, obj):
...             self.__obj = obj
...             self.__prefix = "_%s_" % obj.__class__.__name__
...     def __getattr__(self, name):
...             return getattr(self.__obj, self.__prefix + name)
... 
>>> a = A()
>>> a._A__private() # hard
private A
>>> f = Friend(a)
>>> f._private() # easy
private A

The B instance would refer to A via the Friend instance.

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Nice solution wanted: Hide internal interfaces Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-10-29 17:33 +0100
  Re: Nice solution wanted: Hide internal interfaces andrea crotti <andrea.crotti.0@gmail.com> - 2012-10-29 16:41 +0000
  Re: Nice solution wanted: Hide internal interfaces Benjamin Kaplan <benjamin.kaplan@case.edu> - 2012-10-29 09:41 -0700
  Re: Nice solution wanted: Hide internal interfaces Chris Angelico <rosuav@gmail.com> - 2012-10-30 03:47 +1100
    Re: Nice solution wanted: Hide internal interfaces Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-10-29 17:58 +0100
      Re: Nice solution wanted: Hide internal interfaces Paul Rubin <no.email@nospam.invalid> - 2012-10-29 10:03 -0700
      Re: Nice solution wanted: Hide internal interfaces Grant Edwards <invalid@invalid.invalid> - 2012-10-29 18:00 +0000
      Re: Nice solution wanted: Hide internal interfaces Ian Kelly <ian.g.kelly@gmail.com> - 2012-10-29 13:09 -0600
  Re: Nice solution wanted: Hide internal interfaces Grant Edwards <invalid@invalid.invalid> - 2012-10-29 16:52 +0000
    Re: Nice solution wanted: Hide internal interfaces Johannes Bauer <dfnsonfsduifb@gmx.de> - 2012-10-29 18:01 +0100
      Re: Nice solution wanted: Hide internal interfaces Peter Otten <__peter__@web.de> - 2012-10-29 18:17 +0100
  Re: Nice solution wanted: Hide internal interfaces Peter Otten <__peter__@web.de> - 2012-10-29 18:06 +0100
  Re: Nice solution wanted: Hide internal interfaces Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-10-29 22:37 +0000
  Re: Nice solution wanted: Hide internal interfaces alex23 <wuwei23@gmail.com> - 2012-10-29 18:37 -0700
    Re: Nice solution wanted: Hide internal interfaces andrea crotti <andrea.crotti.0@gmail.com> - 2012-10-30 14:15 +0000

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