Relative imports in Python 3

Question

I want to import a function from another file in the same directory.

Sometimes it works for me with from .mymodule import myfunction but sometimes I get

Answer 1

Hopefully, this will be of value to someone out there - I went through half a dozen stackoverflow posts trying to figure out relative imports similar to whats posted above here. I set up everything as suggested but I was still hitting ModuleNotFoundError: No module named 'my_module_name'

Since I was just developing locally and playing around, I hadn't created/run a setup.py file. I also hadn't apparently set my PYTHONPATH.

I realized that when I ran my code as I had been when the tests were in the same directory as the module, I couldn't find my module:

$ python3 test/my_module/module_test.py                                                                                                               2.4.0
Traceback (most recent call last):
  File "test/my_module/module_test.py", line 6, in 
    from my_module.module import *
ModuleNotFoundError: No module named 'my_module'

However, when I explicitly specified the path things started to work:

$ PYTHONPATH=. python3 test/my_module/module_test.py                                                                                                  2.4.0
...........
----------------------------------------------------------------------
Ran 11 tests in 0.001s

OK

So, in the event that anyone has tried a few suggestions, believes their code is structured correctly and still finds themselves in a similar situation as myself try either of the following if you don't export the current directory to your PYTHONPATH:

1. Run your code and explicitly include the path like so: $ PYTHONPATH=. python3 test/my_module/module_test.py
2. To avoid calling PYTHONPATH=., create a setup.py file with contents like the following and run python setup.py development to add packages to the path:

# setup.py
from setuptools import setup, find_packages

setup(
    name='sample',
    packages=find_packages()
)