[Python-Dev] Import semantics?

Sat Jun 9 00:47:54 CEST 2012

On 6/8/2012 6:41 PM, Ethan Furman wrote:
> Dan Stromberg wrote:
>> On Fri, Jun 8, 2012 at 3:16 PM, Ethan Furman wrote:
>> Dan Stromberg wrote:
>>> Did the import semantics change in cpython 3.3a4?
>>>>>> I used to be able to import treap.py even though I had a treap
>>> directory in my cwd. With 3.3a4, I have to rename the treap
>>> directory to see treap.py.
>>>> Check out PEP 420 -- Implicit Namespace Packages
>> [http://www.python.org/dev/peps/pep-0420/]
>>>>>> Am I misinterpreting this? It seems like according to the PEP, I
>> should have still been able to import treap.py despite having a
>> treap/. But I couldn't; I had to rename treap/ to treap-dir/ first.
>>>> During import processing, the import machinery will continue to
>> iterate over each directory in the parent path as it does in Python
>> 3.2. While looking for a module or package named "foo", for each
>> directory in the parent path:
>>>> * If <directory>/foo/__init__.py is found, a regular package is
>> imported and returned.
>> * If not, but <directory>/foo.{py,pyc,so,pyd} is found, a module
>> is imported and returned. The exact list of extension varies
>> by platform and whether the -O flag is specified. The list
>> here is representative.
>> * If not, but <directory>/foo is found and is a directory, it is
>> recorded and the scan continues with the next directory in the
>> parent path.
>> * Otherwise the scan continues with the next directory in the
>> parent path.
>> I do not understand PEP 420 well enough to say if this is intentional or
> a bug -- thoughts?

I missed the beginning of this discussion and I need some more details.
What directories are on sys.path, where do treap.py and treap/ appear in
them, and is there an __init__.py in treap? At first blush it sounds
like it should continue working.
If you (Dan?) could re-create this in a small example and open a bug,
that would be great.
Eric.