Disabling/Archiving a specific python file from executing when I run Flask

June 23, 2024

So lets say I have multiple python files in the src directory for my Flask application, say

src/
    file1.py
    file2.py
    file3.py
    file4.py

My application uses some optional Machine learning models. I have demarcated file4.py for importing and running the scripts for these ML models. For example,

#file.py script

import some_ML_model

model_init = some_Ml_model()

'''functions that run the model'''

Now I am noticing that file4.py is considerably slowing down my flask application and so I decided to do away with file4.py. I do not want to delete it though to avoid the pain to rewriting the python script in case I need it in the future. I just want flask app not to run file4.py when I run my flask application. Is there any way to tell flask not to run file4.py when I load my flask application? Or is there anyway I can archive file4.py somewhere within my flask application? Like what is the best practice? I have a hunch that I need to make changes to .flaskenv but would appreciate technical help.

>Solution :

You can prevent Flask from running file4.py by simply not importing it in your application. However, if you want to keep file4.py in your project for future use without Flask executing it, you can move it to a different directory that is not included in the Flask application context.

Here’s a structured response you can copy-paste directly to Stack Overflow:

How to exclude a specific file from running in a Flask application?

I have a Flask application with the following directory structure:

src/
    file1.py
    file2.py
    file3.py
    file4.py

My application uses some optional Machine Learning models, which are imported and run in file4.py. Here’s a simplified version of file4.py:

# file4.py

import some_ML_model

model_init = some_ML_model()

# Functions that run the model

I’ve noticed that file4.py significantly slows down my Flask application. I don’t want to delete it because I might need it in the future. I just want to prevent Flask from running file4.py when I start the application.

What is the best practice to achieve this?

Solution:

To prevent file4.py from running, simply don’t import it in your Flask application. You can also move file4.py to a different directory to ensure it’s not included accidentally. Here’s how you can organize your files:

src/
    file1.py
    file2.py
    file3.py
    optional_ml/
        file4.py

By moving file4.py to the optional_ml/ directory, you ensure that it’s not executed by Flask unless you explicitly import it. This way, file4.py remains in your project for future use but does not affect your Flask application’s performance.

You can then update your imports in your main Flask application code to exclude file4.py.

For example, in app.py or wherever you manage your Flask app initialization, make sure you only import the necessary files:

# app.py

from src import file1
from src import file2
from src import file3

# Do not import file4 to prevent it from running
# from src import file4  # This line should be commented out or removed

if __name__ == '__main__':
    app.run()

By following this approach, you keep file4.py in your project without running it unintentionally, maintaining your application’s performance.

This should help you organize your Flask application and prevent file4.py from running without