Is there a way to return value to outside of dash app

[markus_zhang]

Hi experts,

I have a Dash application that consists of several dropdown menus and one button. What I’d like to do is to return the content in the dropdown menu as a list to another python program that uses that list to query a SQL Server, and the result will be stored in a Pandas Dataframe and export back to the Dash app and display as a Dash-table.

I can move data into Dash app by programming it as a function and pass the Dataframe as a parameter. However I’m not sure how to get the list out from the Dash app. I can add an app-callback decorator using the button as input, but where should it output to? The only solution I found is to use a global list in the main program and let Dash app modifies it.

I’m wondering if there is better way to achieve this? I found a similar question:

Dash callback return Value

If you create a Dash app like this: app = Dash(__name__, static_folder='static') And create a folder static in the same directory as the Python script, then the contents of that directory will be accessible via the web. So you can have you Dash callback create the excel file into that folder and then return the URL to the file. That URL will by default be /static/some_file.xlsx.

But I’m asking to return the list to the main program, not to store it as a file. Thanks in advance~