Import Object Declared Inside __init__.py

I'm having trouble understanding how objects declared inside '__init__.py' are/should be imported to other files. I have a directory structure like so top/ | |_lib/ |_ __init

Solution 1:

Generally speaking, I think it's best practice to have the data funnel up to __init__.py from the modules/subpackages rather than needing to rely on data from __init__.py in the surrounding modules. In other words, __init__.py can use one.py, but one.py shouldn't use data/functions in __init__.py.

Now, to your question...

It works in top because python does a relative import (which is gone in python3.x IIRC, so don't depend on it ;-). In other words, python looks in the current directory for a module or package name lib and it imports it. That's all fine so far. running from lib.one import a first imports lib (__init__.py) which works fine. Then it imports one -- lib still imports ok from one because it's relative to your current working directory -- Not relative to the source file.

When you move into the lib directory, python can no longer find lib in the current directory making it not importable. Note that with most packages, this is fixed by installing the package which puts it someplace that python can find it without it needing to be in the current directory.