Confused about __init__.py and importing

Question

So I have a directory setup like so:

some_dir/
 foo/
 bar/
 test.py
 src/
 __init__.py
 data/
 __init__.py
 utils.py

I want to import utils.py from my test.py module.

import sys.path
sys.path.append("../../")
from src import data
data.utils // this throws an error AttributeError: module 'src.data' has no attribute 'utils'

But when I do:

import sys.path
sys.path.append("../../")
from src.data import utils 

Everything works, why is this?

• Klaus D.: utils has never been imported.

Answer 1

a) from src.data import utils will import utils.py, so everything is ok.

b) from src import data will just import the data package, never import utils.py, if you want, you need add explicit import in __init__.py under the folder data, something like follows:

1) If need to support both python3 & python2:

__init__.py:

import src.data.utils # absolute import

Or:

__init__.py:

from . import utils # relative import

2) If just need to support python2, make it simple:

__init__.py:

import utils

Then, when package imported, the __init__.py under this package will also be executed.