Using git submodule to import a python project

Question

(I realise there are a lot of questions on StackOverflow relating to python relative imports; I suspect also that I'm doing this all wrong; but here goes anyway ..)

I have a python project (mysubmod) organised as follows:

/__init__.py
/lib
- /__init__py
- /foobar.py
/models
- /__init__.py
- /hello.py

Importantly:

• /models/hello.py imports lib.foobar
• /models/hello.py has a main block which runs some tests

I then have a second project (myproj) into which I've imported mysubmod as a git submodule; myproj is now organised as follows -

/mysubmod
/scripts
- /__init__.py
- /__test.py

Where:

• scripts/test.py imports mysubmod.models.hello

However when I run /scripts/test.py from the command line, the interpreter now complains that mysubmod/models/hello.py can no longer find lib.foobar.

Reload.

Changed mysubmod/models/hello.py so it now imports ..lib.foobar

Now I can run /scripts/test.py without complaint, but I can no longer run any of the submod scripts as files from the command line; I can only run them as modulles using the python -m option.

Also I can no longer run the submod project files on a standalone basis, even with the -m option, as the interpreter complains about 'Attempted relative import beyond toplevel package'; I have to go up a directory level, ie can only really run mysubmod from the myproj root (where it has mysubmod as the root level directory).

This all seems pretty unsatisfactory. I want to be able to:

• use git submodule to import mysubmod into myproj so that it 'just works'
• continue to be able to develop mysubmod on a standalone basis (ie run scripts as files not modules)

Does anyone have any views on how to do this ? Any views on best practices with respect to git submodule and python ?

Thanks.

Answer 1

OK the answer is (after many wrong turns)

• add a single top level package mysubmod (eg 'helloworld')
• with mysubmod imported into myprod as a submodule, symbolically link the helloworld package into the myprod root ('ln -s mysubmod/helloworld helloworld')

This way, the package structure is maintained whether you are working with the submod as a submodule or on a standalone basis.

Answer 2

You could also add mysubmod to sys.path when you starting your myproj. Then mysubmod/models/hello.py will find lib.foobar.