Auto‑Copy Important Files from a USB Drive with a Simple Python Script

How to Detect USB Insertion?

On macOS/Linux a USB drive is mounted under the /Volumes directory. By periodically scanning this directory you can detect when a new folder appears, indicating that a USB has been inserted.

How to Selectively Copy Files?

After confirming insertion, you may want to copy only certain files—e.g., documents, presentations, or files smaller than a given size—while ignoring large media files.

Recursively Traversing Files with os.walk

The os.walk function walks through a directory tree, yielding each directory and file, which allows you to examine every file on the USB.

Copying Files with shutil

The shutil.copy2 function copies a file while preserving metadata. Combined with os.path.getsize you can filter files by size (e.g., only copy files smaller than 3 MiB).

Filtering by Extension with Regular Expressions

Import the re module and use a regular expression to match desired file extensions such as .docx or .ppt. This lets you skip unwanted media files.

Filtering by Modification Time

By checking a file’s modification timestamp you can copy only files that were recently added or changed, which is useful for incremental backups.

All of the above logic can be combined into a short Python script that runs in the background, sleeps for a few seconds between scans, and automatically copies selected files from any newly inserted USB drive to a target directory. The example was tested on macOS; it works similarly on Linux and can be adapted for Windows with minor changes.