CODEWITHSUNDEEP
pythonpython-3.ximport
dreamzboy
dreamzboy

Reputation: 841

Having Trouble with Import Statement in Python

My current projects are structured like so.

python/
    __init__.py
    project_1/
        __init__.py
        program_1.py
    project_2/
        __init__.py
        program_2.py
    project_3/
        __init__.py
        program_3.py

I wanted to import a class from project_3/program_3.py, called INFO, from both project_1/program_1.py and project_2/program_2.py. In both my program_1.py and program_2.py, I've tried the following import statements that didn't work.

Edit - I typically "cd" into project_1 and run my program_1.py from there.

from project_3.program_3 import INFO

Traceback (most recent call last):
  File "./program_1.py", line 43, in <module>
    from project_3.program_3 import INFO
ImportError: No module named 'project_3'

from python.project_3.program_3 import INFO

Traceback (most recent call last):
  File "./program_1.py", line 43, in <module>
    from python.project_3.program_3 import INFO
ImportError: No module named 'python'

The only way for me to import class INFO into program_1.py and program_2.py is by copying program_3.py in both program_1 and program_2's folder. My import in program_1 and program_2's statement would become:

python/
    __init__.py
    project_1/
        __init__.py
        program_1.py
        program_3.py
    project_2/
        __init__.py
        program_2.py
        program_3.py
    project_3/
        __init__.py
        program_3.py

from program_3 import INFO

This is quite inconvenience because now I have to update program_3.py in all 3 locations. Assuming my the way I structured my project folder is retarded:

I have read the python documentation but it didn't say anything regarding importing classes from one subfolder to another. I also looked at another post from Stack Overflow as well but it didn't have the same structure as mine.

Update 1 - It's important to note that I'm merely using project_1/2 as folder to organized my projects. I originally had init.py in all my folders because I have no clue what I'm doing. The only module/package that I wanted to import in my project_1/program_1.py is from project_3/program_3.py. Example:

python/
    project_1/
        program_1.py
    project_2/
        program_2.py
    project_3/
        __init__.py
        program_3.py

Upvotes: 0

Views: 417

Answers (2)

Gerges
Gerges

Reputation: 6519

When using submodules, you need to use relative imports. In the example provided, importing program_3 from program_1 should be :

from ..project_3 import program_3

and then you can use the INFO class: program_3.INFO.

This works if your executable file is outside the script, that is the file which uses the module python in the example should be outside the python module.

If parts of the python package are executed as a script, the -m option should be passed to the interpreter: 

python3 -m python.project_1.program_1

I hope this helps.

Upvotes: 1

Nicolas M.
Nicolas M.

Reputation: 1478

The previous solution provides me the same error.

I found a fix by using sys:

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

from project_3 import program_3
...

This way, you setup 'python' folder as reference (in your case it's the parent folder but you can select the path you want)

I hope it helps,

Upvotes: 0

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