python: cannot find module in the package

Question

I am creating a python project with the following directory structure:

demos
   demo1.py
kernels
   rbf.py
   ___init__.py

The file rbf.py defines a class called RBF. The __init__.py file in the kernels directory contains the following line:

from .rbf import *

Now the demo1.py contains the following import:

from kernels import RBF

However, this fails with

ImportError: No module named kernels

So the demos folder does not see the kernels package directory. I am at a loss as to what to do to make this work.

Are you running the demo1.py script from the top-level directory (python demos/demo1.py)? — silvado
– silvado, Commented Aug 26, 2015 at 12:16
I ran from demos directory and the top level directory but I got the same error. — Luca
– Luca, Commented Aug 26, 2015 at 12:19

georgebrock · Accepted Answer · 2015-08-26 12:31:42Z

7

You should add the parent directory of kernels to either PYTHONPATH environment variable or directly to sys.path for Python to be able to find the package kernels .

Example of modifying sys.path in demo1.py , assuming both demo and kernels have the same parent directory -

import os, os.path
import sys
sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__),'..')))
from kernels import RBF

What the above does -

__file__ gets the path of the script

os.path.dirname(__file__) - gets the path of the directory containing the file.

os.path.join() - creates the path like - /path/to/demos/.. - depending on the OS.

os.path.abspath - gets the absolute path of the parent directory from /path/to/demos/..

edited Aug 26, 2015 at 12:31

georgebrock

30.5k13 gold badges81 silver badges72 bronze badges

answered Aug 26, 2015 at 12:19

Anand S Kumar

91.4k18 gold badges196 silver badges179 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Luca Over a year ago

Ah ok... Is this very standard thing to do? I never see that in any online python projects....??? Perhaps they take care of it in the setup.py files?

Anand S Kumar Over a year ago

Yes , there are some directories that come up automatically in sys.path , you can try printing it to see what they are . When you install a library , most of the times , they install in the correct directory such that users do not have to add it to PYTHONPATH or sys.path separately .

Aswin Murugesh · Accepted Answer · 2015-08-26 12:19:35Z

0

If both the demo1 and kernels are not in the same folder, you have to add the path to kernels file to the path environmental variable.

import sys
sys.path.append("/path/to/kernels")

answered Aug 26, 2015 at 12:19

Aswin Murugesh

11.1k11 gold badges46 silver badges73 bronze badges

Collectives™ on Stack Overflow

python: cannot find module in the package

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related