Styjun

This is my situation. I have the following directory structure:

$ls -R .:
driver.py package

./package:
dependent.py __init__.py standalone.py

driver.py:

#!/usr/bin/env python

from package.dependent import add_n

if __name__=='__main__':
 print(add_n(2,2))

dependent.py:

#!/usr/bin/env python

from standalone import add_1

def add_n(x, n):
 for _ in range(n):
 x = add_1(x)
 return x

standalone.py:

#!/usr/bin/env python

def add_1(x):
 return x+1

Now depending on my use case, I want to run dependent.py directly or import it into driver.py. This is the problem I'm facing:

• Running dependent.py only works if there is not a dot when importing add_1. If there is one, it throws the following error:

Traceback (most recent call last):
 File "dependent.py", line 3, in <module>
 from .standalone import add_1
ModuleNotFoundError: No module named '__main__.standalone'; '__main__' is not a package

• Running package.py only works if there is a dot when importing add_1. If there is not one, it throws the following error:

Traceback (most recent call last):
 File "driver.py", line 3, in <module>
 from package.dependent import add_n
 File "/home/su0/scratch/package/dependent.py", line 3, in <module>
 from standalone import add_1
ModuleNotFoundError: No module named 'standalone'

I want both scenarios to work. This is because, in the real project, there are dependencies within the package that import other modules. And I want to be able to import it as a package as well. Any help is appreciated.

Thanks.

The best would be to really package the code and then use absolute imports in dependent.py. As a workaround you can however use one of the following options:

Extend the path in driver.py

Before the import package.dependent you can add the following lines:

import sys
sys.path.append('package')

Then use the undotted import statement in dependent.py. This works since now package is on the path to be searched for modules, including standalone.py.

Use conditional imports in dependent.py

You can modify the imports in dependent.py as follows:

if __name__ == '__main__':
 from standalone import ...
else:
 from .standalone import ...