Yet another Python Relative import mishap

Question

#Background and Problem# I'm trying to build a web-scraper to back up my social media accounts (summer project, I know it's useless).

I'm trying to create a nice class structure, so I've come up with the following structure (I accept critique, I'm pretty new to programming):

\social-media-backup

    \Files
        __init__.py
        File.py
        Image.py
        Video.py

    \SocialMedia
        SocialMediaFeed.py
        SocialMediaPost.py
        \Instagram
            __init__.py
            \MediaTypes
                __init__.py
                GraphImage.py
                GraphVideo.py
            \SearchTypes
                __init__.py
                InstagramUser.py
        \Twitter
        \VSCO

(Twitter and VSCO are, for now, empty. Anything without extension and starting with , is a folder. Every file has a class with the same name as the file inside)

#Questions#

1. Where can I learn Python's packaging system definitively? Any book or web-site recommendation?
2. How would I import Image into GraphImage? How would I import File into SocialMediaPost?
3. What do I need to write in __init__.py so as to import SOME_PACKAGE and have it import every module? (e.g.: import Files and have Files.Image and File.Video accessible).

(I know there are a lot of questions. They're written in order of importance)

#To accomplish importing File into SocialMediaPost I've tried:#

from Files.File import File

from ...Files.File import File

import File

from File import File

And almost any combination you can imagine.

I always get an Unable to import, No module named '__main__.Files' or Attempted relative import beyond top-level package.

#Expected behavior#

I'm used to Java's way of doing this, and I cannot figure out how to do this in Python. It seems so messed up. I really miss just adding a package and a folder tree from where the compiler would run.

knocks desk THERE MUST BE A BETTER WAY

##THANKS!!##

Answer 1

Lots of stuff is written about this... however most guides focus on how you do it, not what to do.

How I do it (for small to medium-sized projects):

1. Do not mess with sys.path.
2. Have one "project root" directory with your modules / packages underneath (as you already do).
3. Use absolute imports always, except for "sister" modules.
4. Always run as module, i.e. using python -m foo.bar

Concrete example using your structure. Assuming that your entry point might be in \SocialMedia\SocialMediaFeed.py, use import statements:

• from . import SocialMediaPost (sister module)
• import Instagram (child module)
• from Files import Image (other module)

and run using: python -m SocialMedia.SocialMediaFeed

By running as module, you always have the project root (social-media-backup) added as "search path". This way absolute imports refering to its subfolders always work. By the way, you can print out the module search path using import sys; print(sys.path).

Some of this might seem overcomplicated, but I found that following the above points pays out greatly as soon as you try to package up stuff for installation (keyword setup.py).

Edit: to answer 3rd question: Have __init__.py contain:

from . import File
from . import Image
from . import Video

Answer 2

I would second the comments by Damian and user2357112 - try to avoid name collisions between folder, file and class/function when creating modules.

You probably won't be able to import anything outside of the current working directory without adding it to your PYTHONPATH. Adding a folder to your PYTHONPATH environment variable means that python will always check that folder when importing modules, so you'll be able to import it from anywhere.

There is a good thread on this already that will put you in the right direction: Permanently add a directory to PYTHONPATH? (It's a lot to cover in one post)