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Re: Nice solution wanted: Hide internal interfaces

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2012/10/30 alex23 <wuwei23@gmail.com>:
> On Oct 30, 2:33 am, Johannes Bauer <dfnsonfsdu...@gmx.de> wrote:
>> I'm currently looking for a good solution to the following problem: I
>> have two classes A and B, which interact with each other and which
>> interact with the user. Instances of B are always created by A.
>>
>> 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.
>
> One approach could be to only have the public interface on B, and then
> create a wrapper for B that provides the private interface:
>
>     class B:
>         def public_method(self):
>             pass
>
>     class B_Private:
>         def __init__(self, context):
>             self.context = context
>
>         def private_method(self):
>             # manipulate self.context
>
>     class A:
>         def __init__(self):
>             self.b = B()
>             self.b_private = B_Private(self.b)
>
>         def foo(self):
>             # call public method
>             self.b.public_method()
>
>             # call private method
>             self.b_private.private_method()
>
> It doesn't stop a user from accessing the private methods, but it does
> separate them so they have to *intentionally* choose to use them.
> --
> http://mail.python.org/mailman/listinfo/python-list



Partly unrelated, but you could also define a clear API and expose it
through your __init__.py.

For example:
package/a.py:
class A: pass

package/b.py:
class B:pass

package/__init__.py
from a import A

so now doing "from package import" will only show A.

This doesn't work on the method-level, but it's useful to know and
commonly done in many projects..


In some projects they even use a file "api.py" to you have to
explicitly import

from package.api import ..
(which I think is overkill since __init__.py does the same)

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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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