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From: Ian Kelly <ian.g.kelly@gmail.com>
Date: Sun, 23 Nov 2014 02:56:34 -0700
Subject: Re: unloading a module created with imp.new_module
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Xref: csiph.com comp.lang.python:81356

On Sun, Nov 23, 2014 at 2:48 AM, Ian Kelly <ian.g.kelly@gmail.com> wrote:
> On Sat, Nov 22, 2014 at 11:49 PM, Patrick Stinson <patrickkidd@gmail.com>=
 wrote:
>> If I create a module with imp.new_module(name), how can I unload it so t=
hat all the references contained in it are set to zero and the module is de=
leted? deleting the reference that is returned doesn=E2=80=99t seem to do t=
he job, and it=E2=80=99s not in sys.modules, so where is the dangling refer=
ence?
>
> How are you determining that the module is not deleted?

>From my testing, using Python 3.4:

>>> for i in range(5): imp.new_module('spam')
...
<module 'spam'>
<module 'spam'>
<module 'spam'>
<module 'spam'>
<module 'spam'>
>>> import gc, types
>>> [m for m in gc.get_objects() if isinstance(m, types.ModuleType) and m._=
_name__ =3D=3D 'spam']
[<module 'spam'>]
>>> 42
42
>>> [m for m in gc.get_objects() if isinstance(m, types.ModuleType) and m._=
_name__ =3D=3D 'spam']
[]

In this case one of the created modules was hanging around because it
was still referenced by the special "_" variable of the interactive
interpreter. Evaluating a new expression cleared that out and deleted
the module. Maybe you're seeing the same thing.