How do I import something from a nested child directory with Python?

Question

In my main file (root level), I have:

from deepspeech2_utils import reduce_tensor, check_loss

And I also have an __init__.py that has:

from submodules.deepspeech2 import utils as deepspeech2_utils

I have a directory structure that looks like:

main.py
__init__.py
-submodules
  -deepspeech2
    -utils.py

But I get an error:

    from deepspeech2_utils import reduce_tensor, check_loss
ImportError: No module named deepspeech2_utils

I also tried:

from submodules.deepspeech2.utils import reduce_tensor, check_loss

but get the same error.

What am I doing wrong?

Answer 1

So the way directories are recognized as modules in python is by the presence of an __init__.py file within those directories. These __init__.py files don't need to have code. So change your directory structure to look like this

root
    main.py
    __init__.py
    submodules
        __init__.py
        deepspeech2
            __init__.py
            utils.py

Now once this is done, your import statement (which didn't work without the above directory changes) in __init__.py has a scope, it will not be visible within your main.py - that has a different scope. In order to achieve what you are doing change your import statement in main.py to

from root.deepspeech2_utils import reduce_tensor, check_loss

I have to advise apart from namespacing reasons, importing in __init__.py is not encouraged, since users of your module may just want to import specific things from your module/submodules and your import statements in __init__.py will force them to have more imports than they want. Here is an answer from another post that talks about such concerns in detail