[Python-Dev] Import semantics? (original) (raw)

Eric V. Smith eric at trueblade.com
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 /foo/init.py is found, a regular package is imported and returned. * If not, but /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 /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.

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