Python error "ImportError: No module named"

Python is installed in a local directory.

My directory tree looks like this:

(local directory)/site-packages/toolkit/interface.py

My code is in here:

(local directory)/site-packages/toolkit/examples/mountain.py

To run the example, I write python mountain.py, and in the code I have:

from toolkit.interface import interface

And I get the error:

Traceback (most recent call last):
  File "mountain.py", line 28, in ?
    from toolkit.interface import interface
ImportError: No module named toolkit.interface

I have already checked sys.path and there I have the directory /site-packages. Also, I have the file __init__.py.bin in the toolkit folder to indicate to Python that this is a package. I also have a __init__.py.bin in the examples directory.

I do not know why Python cannot find the file when it is in sys.path. Any ideas? Can it be a permissions problem? Do I need some execution permission?

Based on your comments to orip's post, I guess this is what happened:

1. You edited __init__.py on windows.
2. The windows editor added something non-printing, perhaps a carriage-return (end-of-line in Windows is CR/LF; in unix it is LF only), or perhaps a CTRL-Z (windows end-of-file).
3. You used WinSCP to copy the file to your unix box.
4. WinSCP thought: "This has something that's not basic text; I'll put a .bin extension to indicate binary data."
5. The missing __init__.py (now called __init__.py.bin) means python doesn't understand toolkit as a package.
6. You create __init__.py in the appropriate directory and everything works... ?

Does

(local directory)/site-packages/toolkit

have a __init__.py?

To make import walk through your directories every directory must have a __init__.py file.