Importing another project as modules in python

Question

Suppose I have a project in the following structure

projectfoo/
|- mymodule/
|--|- __init__.py
|--|- library.py
|- preprocessor.py

and in the __init__.py in mymodule looks like this

from . import library #library itself has other functions

def some_function():
    blar blar blar...

and the preprocessor.py would look like follows

import mymodule

def main():
    something()

def something():
    mymodule.some_function() # calls the function defined in __init__.py

if __name__ == '__main__':
    main()

Then I started projectbar, which is using a lot of common code from projectfoo. So instead of copying and pasting code between projects, I wish to import projectfoo into project bar, as follows.

projectbar/
|- projectfoo/
|--|- mymodule/
|--|--|- __init__.py
|--|--|- library.py
|--|- preprocessor.py
|- index.py

So I am trying to import preprocessor in my index.py as follows

from projectfoo import preprocessor

However I am getting an error saying preprocessor.py is now unable to import mymodule.

ImportError: No module named 'mymodule'

Am I doing this correctly? I am using python3.4 running in ubuntu 14.04 in my setup.

EDIT: I also tried adding __init__.py to projectfoo, but I am still getting the same error

Answer 1

You are getting this error because you did not added the path of preprocessor as a library package

from sys import path as pylib #im naming it as pylib so that we won't get confused between os.path and sys.path 
import os
pylib += [os.path.abspath(r'/projectfoo')]
from projectfoo import preprocessor

FYI: os.path will return the absolute path. but sys.path will return the path env. variable in system settings.

Hope it helps.