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Download a file

This recipe downloads a file from a Unity Catalog volume using the Databricks SDK for Python.

note

Unlike notebooks, Databricks Apps does not support mounting Unity Catalog volumes and directly reading and writing files. As this code snippet demonstrates, each file needs to be downloaded to the app compute before being able to manipulate it.

Code snippet​

app.py
import reflex as rx
import os
from databricks.sdk import WorkspaceClient

w = WorkspaceClient()

class DownloadFileState(rx.State):
    download_file_path: str = ""

    async def handle_download(self):
        response = w.files.download(self.download_file_path)
        file_data = response.contents.read()
        file_name = os.path.basename(self.download_file_path)

        return rx.download(data=file_data, filename=file_name)

Resources​

Permissions​

Your app service principal needs the following permissions:

  • USE CATALOG on the volume's catalog
  • USE SCHEMA on the volume's schema
  • READ VOLUME on the volume

See Privileges required for volume operations for more information.

Dependencies​

requirements.txt
databricks-sdk
reflex