Python3 Module import from different files-CodePudding

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.

CodePudding user response：

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

CodePudding user response：

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 in 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