Python3 Module import from different files

Question

I have a project in python that uses a file structure similar to this:

program/
    main.py
    SubFolder/
        module1.py
        module2.py
    TestFolder/
        test.py

In this structure main.py imports module2.py and module2.py imports module1.py. Also test.py imports module2.py.

I have two problems with the imports in this folder structure.

When running the main.py the import in module2.py is as follows:

from SubFolder.module1 import *

Here the the folder of main.py is set as the root folder and all the imports are done from there. While when I run module2.py directly the import should be as follows:

from module1 import *

Because now the root folder is the folder of module2.py. This is a problem, because now the import statements constantly need to be changed when running from different files. Is there any solution to this?

The second problem is when I want to run test.py, this file imports module2.py. The way to import this should be:

from ..SubFolder.module2 import *

But this gives the following error message:

    from ..SubFolder.module2 import *
ImportError: attempted relative import with no known parent package

I have looked at a lot of solutions for this, but could not find one that worked. Is there any way to fix this.

Is there someone that could explain to me how I could resolve these issues?

I have already looked at this: Relative imports in Python 3, but this does not resolve my issue.

Akado2009 · Answer 1 · 2022-03-24T15:16:44.103

0

I suggest you just create empty __init__.py files in subFolder and then import it as following: from subFolder.module1 import *.

edited Mar 24 '22 at 15:16

answered Mar 24 '22 at 14:46

Akado2009

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Electron X · Accepted Answer · 2022-03-25T19:00:31.127

create a __init__ file

program/
    main.py
    SubFolder/
        __init__.py
        module1.py
        module2.py
    TestFolder/
        test.py

in __init__.py, import all the files in same directory

from SubFolder.module1 import *
from SubFolder.module2 import *

in main.py, import Subfolder

from Subfolder import *
function_inside_module1()

Now you can access any object in module1 and module 2.
__init__.py works just like def __init__ in a class function,
It will execute itself once the parent directory (module) is imported.
so in main.py, it will be executed as:

from SubFolder.module1 import *
from SubFolder.module2 import *
function_inside_module1()

Note: with import Subfolder you will need to call functions like this:

import Subfolder
Subfolder.function_inside_module1()

we now look at the module 2 import problem, this is already solved when __init__.py is created. because now python sees it as a module and can be imported anywhere.
in module2,

from SubFolder.module1 import *

will now work at any working directory

same for test.py,

from SubFolder.module2 import *

will also work in test.py

Warning: Do not do this in module files and expect normal results

#  in module1:
from SubFolder.module1 import *
#  AND in module2:
from SubFolder.module2 import *

this will cause circular import and result in import error or names being undefined

damn, this took more time than I thought, experimented with modules, interesting ques — Electron X, Mar 24 '22 at 15:42
Thanks for the explenation, the `__init__` file seems to work for the `main.py`. Only `module1.py` and `test.py` now both give the error: `from SubFolder.module1 import * ModuleNotFoundError: No module named 'SubFolder'` Is this because of my IDE? I am using Visual Studio Code. — LRV2K1, Mar 25 '22 at 14:52
@LRV2K1 I am not very sure if it's your IDE, I am using pycharm and it worked but it may be other factors. maybe you will want to see [this](https://stackoverflow.com/questions/33862963/python-cant-find-my-module) — Electron X, Mar 25 '22 at 19:04
Thanks for the awnsers, I checked in pycharm and it does work there. Therefore I will for now be switching to pycharm for this project. — LRV2K1, Mar 25 '22 at 20:38

Python3 Module import from different files

2 Answers2