gistfile1.txt

[~/tmp/ppathtest]$ mkdir bar
[~/tmp/ppathtest]$ mkdir foo/package
[~/tmp/ppathtest]$ mkdir bar/package

[~/tmp/ppathtest]$ echo '__import__("pkg_resources").declare_namespace(__name__)' > bar/package/__init__.py
[~/tmp/ppathtest]$ echo '__import__("pkg_resources").declare_namespace(__name__)' > foo/package/__init__.py

[~/tmp/ppathtest]$ touch foo/package/herp.py
[~/tmp/ppathtest]$ touch bar/package/herp.py

[~/tmp/ppathtest]$ tree
.
├── bar
│   └── package
│       ├── __init__.py
│       ├── __init__.pyc
│       ├── herp.py
│       └── herp.pyc
└── foo
    └── package
        ├── __init__.py
        ├── __init__.pyc
        ├── herp.py
        └── herp.pyc


[~/tmp/ppathtest]$ PYTHONPATH=bar:foo python2.6 -c 'from package import herp; print herp.__file__'
/Users/jyrki/tmp/ppathtest/bar/package/herp.py
[~/tmp/ppathtest]$ PYTHONPATH=bar:foo python2.7 -c 'from package import herp; print herp.__file__'
/Users/jyrki/tmp/ppathtest/foo/package/herp.py