using del() to 'unimport'

[Steve Holden]

"TeaAndBikkie" <teaandbikkie at aol.com> wrote ...
> >From: donnal at donnal.net  (Donnal Walter)
> >
> >When the the following module is imported, I want only 'MyClass' (NOT
> >'Useful' and 'Mixin1') to be publicly accessible.
> >
> >======= mymodule.py ==================
> >from utilities import Useful, Mixin1
> >
> >class MyClass(Useful, Mixin1): pass
> >
> >del(Useful)
> >del(Mixin1)
> >======================================
>
> One alternative is not to import the names in the first place, eg.
>
> import utilities
> class MyClass(utilities.Useful, utilities.Mixin1): pass
>
> Then you would only have "utilites" in the main namespace.
>

The implication of the original post is that MyClass is being defined in its
own module. In that case, wouldn't it make more sense to set the __all__
attribute in the module to decide which names are imported into the client's
namespace? From 6.12 in the Reference Manual:

"""
The public names defined by a module are determined by checking the module's
namespace for a variable named __all__; if defined, it must be a sequence of
strings which are names defined or imported by that module. The names given
in __all__ are all considered public and are required to exist. If __all__
is not defined, the set of public names includes all names found in the
module's namespace which do not begin with an underscore character ("_").
"""

So a simple

    __all__ = (MyClass, )

would seem to answer here.

regards
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Steve Holden                                  http://www.holdenweb.com/
Python Web Programming                 http://pydish.holdenweb.com/pwp/
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