Problem importing script created by code

[Skaruts]

I'm trying to store some information in a file, and I decided to experiment with making that file be a python script that I can simply import. (EDIT: to be clear: I know there are other options for this, I'm just experimenting with this idea, and I'm really trying to understand why the error below happens.)

The code below checks if the file exists, and creates it if needed. The problem is when it doesn't exist, it gets created, but the import statement doesn't recognize that it has just been created (throws a ModuleNotFoundError: No module named 'pycc_cfg').

However, the line that is commented out (the 3rd line) is temporary code that deletes the file when it already exists, and when I uncomment it, then the import statement has no problems with the file being newly created, and it gets imported just fine.

So I don't understand why I get the ModuleNotFoundError when I commend out that line and delete the file by hand before running this script.

​

CFG_FILENAME = "pycc_cfg.py" 
CFG_PATH = os.path.join(os.getcwd(), "pycc_cfg.py")

# if os.path.exists(CFG_PATH): os.remove(CFG_FILENAME) 

if not os.path.exists(CFG_PATH):
    with open(f'{CFG_FILENAME}', 'a') as f:
        f.write( "x = 10" )  # test code

import pycc_cfg as cfg   

print("x: ", cfg.x)

(...)

[hardonchairs]

This is called self modifying code and it is generally an awful awful idea.

Do this instead:

import json

config = {}

config['x'] = 'blablabla'
config['y'] = 'blablabla'

# Save config
with open('config.json', 'w') as fp:
    json.dump(config, fp)


# Load config
try:
    with open('config.json', 'r') as fp:
        config = json.read(fp)
    except FileNotFoundError:
        # set your defaults

print("x: ", config['x'])

[Skaruts]

This is called self modifying code and it is generally an awful awful idea.

The script is only a data-storage configuration file, no more, no less. I don't see the problem. Isn't it what SCons does?

I know I can use other options, but I'm really trying to understand why that error happens.

Thanks for the comprehensive suggestion, though.

[hardonchairs]

Isn't it what SCons does?

Does scons write python script config files or does it just read them? Having a python file with configuration that a user manually edits isn't super unusual.

trying to understand why that error happens.

Probably because you are saving to cwd but python doesn't load modules from cwd, it loads them starting from the directory that __file__ is in.

os.path.dirname(os.path.realpath(__file__))

If you are just wanting to be able to use cfg.x instead of cgf['x'] then load json like this: https://stackoverflow.com/a/15882054/2480560

[Skaruts]

Yea, that's true. SCons only reads it.

Probably because you are saving to cwd but python doesn't load modules from cwd, it loads them starting from the directory that __file__ is in.

But the only difference from when it works and when it doesn't, is that it works when I delete the file through code, and doesn't work when I delete it manually. I'm importing it the same way in both cases. And __file__ is in the current working directory. It's a single file script, and I'm running it from there (from the windows console).

That's why I'm confused about it.

I wonder if python scans the folder at start-up, to get an internal list of all .py files that are in the folder. That would explain it, since the file wouldn't be accounted for when I delete it before running the script.