seems like a bug in isinstance()

[dmitrey]

On May 7, 11:53 am, Gregory Ewing <greg.ew... at canterbury.ac.nz> wrote:
> Chris Rebert wrote:
> > This is because you did `from Point import
> > ...` in file2.py, whereas in file1.py you did `from
> > openopt.kernel.Point import ...`. These 2 different ways of referring
> > to the same module are sufficient to "trick"/"outsmart" (C)Python and
> > cause it to import the same module twice
>
> That can't be the whole story, because those two ways of
> referring to the module *should* have returned the same
> module object, even though one is absolute and the other
> relative.
>
> I suspect what's happened is that somehow sys.path contains
> both the directory containing .../openopt *and* the directory
> .../openopt/kernel, and the second import is picking up
> Point.py a second time as though it were a top-level module.
>
> This could have happened by starting an interactive session
> while cd'ed to .../openopt/kernel, or by launching a .py
> file from there as a main script.
>
> The solution is to make sure that sys.path only contains the
> top level directories of the package hierarchy, and doesn't
> also contain any of their subdirectories.
>
> Always using absolute imports may be a good idea stylistically,
> but in this case it will only mask the symptoms of whatever
> is really wrong, and further problems could result from the
> same cause.
>
> --
> Greg

> I suspect what's happened is that somehow sys.path contains
both the directory containing .../openopt *and* the directory
.../openopt/kernel
Yes, you are right. But I have to do it due to another issue I haven't
solved yet: 	Python3 imports don't see files from same directory
http://groups.google.com/group/comp.lang.python/browse_thread/thread/9470dbdacc138709#

Regards, D.