macOS External Drive Formatter

A minimal, safe, and interactive Python utility that lists and formats external drives on macOS using the native diskutil command.

Overview

• Lists connected disks and prompts the user to choose one for formatting.
• Supports ExFAT (recommended) and FAT32.
• Uses macOS’ built-in diskutil for reliable disk operations.
• Includes confirmation prompts to reduce risk of accidental data loss.

Requirements

• macOS
• Python 3.7 or later
• Administrator privileges (required to run diskutil erase operations)

Quick start

1. Clone the repository:

   git clone https://github.com/<your-username>/macos-drive-formatter.git
   cd macos-drive-formatter

2. (Optional) Create and activate a virtual environment:

   python3 -m venv venv
   source venv/bin/activate

3. Run the script:

   python3 format_external_drive.py

Usage summary

1. The script runs diskutil list to display available disks.
2. Enter the disk identifier (for example: disk4).
3. Confirm the selected disk (explicit y required).
4. Choose the filesystem format:
   • 1 → ExFAT (recommended: cross-platform)
   • 2 → FAT32 (legacy compatibility)
5. Provide an optional volume name (defaults to MyUSB).
6. Confirm the final destructive action before the script invokes diskutil eraseDisk.

Example session === macOS External Drive Formatter ===

🔍 Listing available disks...

/dev/disk4 (external, physical): #: TYPE NAME SIZE IDENTIFIER 0: FDisk_partition_scheme *30.9 GB disk4 1: Linux 28.2 GB disk4s3

Enter the disk identifier (e.g. disk4): disk4
⚠️ You chose /dev/disk4. Continue? (y/n): y

Choose the filesystem format:

1. ExFAT (recommended)
2. FAT32 (for legacy systems)
   Enter your choice (1 or 2): 1

Enter a name for the new volume (e.g. MyUSB): BackupDrive
This will ERASE all data on the disk. Proceed? (y/n): y

✅ Disk /dev/disk4 formatted successfully as ExFAT (BackupDrive)

How it works The script delegates formatting to diskutil:

diskutil eraseDisk ExFAT MyUSB GPT /dev/disk4

This leverages macOS's native disk management for compatibility and reliability.

Safety & disclaimers

• This tool will irreversibly erase data on the selected disk.
• Double-check the disk identifier before confirming.
• The author is not responsible for data loss caused by misuse.

Development & contributions

• Contributions and improvements are welcome. Open an issue or pull request with suggested changes.
• Future enhancements may include additional filesystem support (APFS, HFS+), a GUI, and progress reporting.

Author Dabwitso Mweemba — Co-founder & Lead Developer at Code Savanna
GitHub • LinkedIn

License This project is released under the MIT License. See the LICENSE file for details.