On Thu, Mar 15, 2018 at 5:25 AM, Brendan Barnwell <brenb...@brenbarn.net> wrote:
> On 2018-03-14 04:18, Steven D'Aprano wrote:
>>
>> Apart from intentionally manipulating sys.modules or the import system,
>> or playing file system tricks like hard-linking your files, under what
>> circumstances can this occur by accident?
>
>
> It can occur if a given directory winds up appearing twice on the
> import path. For instance, if /foo is on the path and /foo/bar is a package
> directory with /foo/bar/baz as a subpackage directory, then you can do "from
> bar import baz" and "import baz" and wind up with two different module
> objects referring to the same module.
>
> This usually happens when code starts adding paths to sys.path.
> This is in some sense "manipulating the import system" but it's something
> that a fair number of libraries do in various contexts, in order to be able
> to do things like import plugins without requiring the user to make those
> plugins available on the default import path.
Or by running something that's part of a package, thus making the
current directory automatically available.
spam/
__init__.py
spam.py
ham.py
python3 spam/spam.py
If it now says "from spam import ham", is it going to get ham.py, or
is it going to try to pull up ham from spam.py?
ChrisA
_______________________________________________
Python-ideas mailing list
Python-ideas@python.org
https://mail.python.org/mailman/listinfo/python-ideas
Code of Conduct: http://python.org/psf/codeofconduct/
