Executing & accessing python module code with __all__ in __init__.py

Question

So I'm trying to write a simple wsgi python module where I use __init__.py to bring in variables & functions from another file but I can't seem to get the module to load. I keep getting the "AttributeError"

I've tried fiddling with some variations of "from . import mydb" and "from . import *" but haven't had any luck.

The code isn't anything complicated, see below. A wsgi loads a simple Flask app and then tries to load a module and access a single variable in the module, but I can't seem to get it to work. I feel like I'm missing something blindingly obvious...

Edit: As user2357112 correctly pointed out I'm trying to run a sub package from my app directory (/var/www/html/hellopy/app/config/). I wrote out the paths but managed to get them wrong.

Still fiddling with it trying to figure it out...

/var/www/html/hellopy/hellopy.wsgi:

import sys
import logging

from hellopy import app as application
from app import config
mydbkey = config.dbkey

# Optional: Set logging
logging.basicConfig(stream=sys.stderr)
sys.stderr = sys.stdout

/var/www/html/hellopy/hellopy.py:

import sys
from flask import Flask

sys.path.insert(0, '/var/www/html/hellopy')

app = Flask(__name__)

#to restart apache, sudo systemctl restart httpd.service

@app.route('/')
def hello_world():
    return 'Hello, World! Py found! Updated right now!, '

if __name__ == "__main__":
    application.run()

/var/www/html/hellopy/app/config/init.py

__all__ = ["mydb"]

/var/www/html/hellopy/app/config/mydb.py

dbkey = "abc123"

The error:

[Thu Mar 13 17:15:47.192392 2025] [wsgi:error] [pid 5735:tid 5841] [remote 127.0.0.1:37416] mod_wsgi (pid=5735): Failed to exec Python script file '/var/www/html/hellopy/hellopy.wsgi'. [Thu Mar 13 17:15:47.192441 2025] [wsgi:error] [pid 5735:tid 5841] [remote 127.0.0.1:37416] mod_wsgi (pid=5735): Exception occurred processing WSGI script '/var/www/html/hellopy/hellopy.wsgi'. [Thu Mar 13 17:15:47.192611 2025] [wsgi:error] [pid 5735:tid 5841] [remote 127.0.0.1:37416] Traceback (most recent call last): [Thu Mar 13 17:15:47.192706 2025] [wsgi:error] [pid 5735:tid 5841] [remote 127.0.0.1:37416] File "/var/www/html/hellopy/hellopy.wsgi", line 8, in [Thu Mar 13 17:15:47.192726 2025] [wsgi:error] [pid 5735:tid 5841] [remote 127.0.0.1:37416] mydbkey = config.dbkey [Thu Mar 13 17:15:47.192732 2025] [wsgi:error] [pid 5735:tid 5841] [remote 127.0.0.1:37416] ^^^^^^^^^^^^ [Thu Mar 13 17:15:47.192747 2025] [wsgi:error] [pid 5735:tid 5841] [remote 127.0.0.1:37416] AttributeError: module 'app.config' has no attribute 'dbkey'

EDIT2:

Thanks to user2357112 I figured out this works:

Edit to /var/www/html/hellopy/hellopy.py:

#!/var/www/html/hellowpy/venv/bin/python
import sys
import logging
logger = logging.getLogger(__name__)
from hellopy import app as application
from app import config
mydbkey = config.mydb.dbkey
# Optional: Set logging
logging.basicConfig(stream=sys.stderr)
sys.stderr = sys.stdout
logger.error("Logged message from hellopy " + mydbkey)

Edit to /var/www/html/hellopy/app/config/init.py:

# -*- coding: utf-8 -*-
from . import mydb
__all__ = ["mydb"]

But it's not quite what I wanted. I wanted the dbkey object to be part of config object without having to dump it all into the init.py file.

I know that's the "right" way to do it, that I shouldn't just put a ton of stuff in init.py but I haven't quite figured out how to do it :)

Definitely getting closer :)

Answer 1

app.config is supposed to be an attribute on this thing here:

app = Flask(__name__)

You set and retrieve entries on it with

app.config['dbkey'] =  'abc123'

or

mydbkey = app.config['dbkey']

Not with __init__.py or __all__ or any of the other stuff you tried.

(You can also load configuration from environment variables, or data files, or other sources, as described in the docs.)

---

From the error message, it looks like you created a package named app with a submodule named config (neither of which you showed us), and expected that submodule to have a dbkey attribute for some reason. But your __init__.py is for the hellopy package, and all it does is make it so from hellopy import * imports the hellopy.mydb submodule.

It doesn't do anything related to the app.config module you created, or the app.config mapping you should have been accessing.

Answer 2

Thanks to user2357112 I figured it out, they key was I needed an _init_.py in the config folder in order to expose mydb's members later on, like so:

/var/www/html/hellopy/hellopy.wsgi

    #!/var/www/html/hellowpy/venv/bin/python

    from hellopy import app as application
    from app import config
    mydbkey = config.dbkey

/var/www/html/hellopy/hellopy.py

    # /var/www/myflaskapp/myapp.py
    import sys
    from flask import Flask

    sys.path.insert(0, '/var/www/html/hellopy')

    app = Flask(__name__)

    #to restart apache, sudo systemctl restart httpd.service

    @app.route('/')
    def hello_world():
        return 'Hello, World! Py found! Updated right now!, '

    if __name__ == "__main__":
        application.run()

/var/www/html/hellopy/app/__init__.py

    from app.config import mydb
    config = mydb                   # this was the part I was missing, I need this to explose mydb.py's variables later on in my application.

/var/www/html/hellopy/app/config/__init__.py

    # -*- coding: utf-8 -*-
    __all__ = ["mydb"]


/var/www/html/hellopy/app/config/mydb.py

    dbkey = "abc123"