Python: How to search only USB flash drives?

Question

I have a Python script which is designed to be run from a USB flash drive, and would not work if run from a PC hard drive, so it is safe to assume all copies exist on connected USBs.

I have another script designed to be run from the computer hard drive which seeks these USB scripts and configures them all in a certain way. Obviously to save time I do not want to search the entire hard drive when I know they are only on USBs. Is there a way to only search files on a connected USB, skipping searching local drives, through checking drive letters or the like?

Answer 1

Here's some example code to determine the drive type for every active logical drive on Windows, using ctypes...

import ctypes

# Drive types
DRIVE_UNKNOWN     = 0  # The drive type cannot be determined.
DRIVE_NO_ROOT_DIR = 1  # The root path is invalid; for example, there is no volume mounted at the specified path.
DRIVE_REMOVABLE   = 2  # The drive has removable media; for example, a floppy drive, thumb drive, or flash card reader.
DRIVE_FIXED       = 3  # The drive has fixed media; for example, a hard disk drive or flash drive.
DRIVE_REMOTE      = 4  # The drive is a remote (network) drive.
DRIVE_CDROM       = 5  # The drive is a CD-ROM drive.
DRIVE_RAMDISK     = 6  # The drive is a RAM disk.

# Map drive types to strings
DRIVE_TYPE_MAP = { DRIVE_UNKNOWN     : 'DRIVE_UNKNOWN',
                   DRIVE_NO_ROOT_DIR : 'DRIVE_NO_ROOT_DIR',
                   DRIVE_REMOVABLE   : 'DRIVE_REMOVABLE',
                   DRIVE_FIXED       : 'DRIVE_FIXED',
                   DRIVE_REMOTE      : 'DRIVE_REMOTE',
                   DRIVE_CDROM       : 'DRIVE_CDROM',
                   DRIVE_RAMDISK     : 'DRIVE_RAMDISK'}


# Return list of tuples mapping drive letters to drive types
def get_drive_info():
    result = []
    bitmask = ctypes.windll.kernel32.GetLogicalDrives()
    for i in range(26):
        bit = 2 ** i
        if bit & bitmask:
            drive_letter = '%s:' % chr(65 + i)
            drive_type = ctypes.windll.kernel32.GetDriveTypeA('%s\\' % drive_letter)
            result.append((drive_letter, drive_type))
    return result


# Test
if __name__ == '__main__':
    drive_info = get_drive_info()
    for drive_letter, drive_type in drive_info:
        print '%s = %s' % (drive_letter, DRIVE_TYPE_MAP[drive_type])
    removable_drives = [drive_letter for drive_letter, drive_type in drive_info if drive_type == DRIVE_REMOVABLE]
    print 'removable_drives = %r' % removable_drives

...which prints...

C: = DRIVE_FIXED
D: = DRIVE_FIXED
E: = DRIVE_CDROM
removable_drives = []

...before inserting a USB stick and...

C: = DRIVE_FIXED
D: = DRIVE_FIXED
E: = DRIVE_CDROM
F: = DRIVE_REMOVABLE
removable_drives = ['F:']

...afterwards.

Once you've got the list of removable drives, you can simply use os.walk() on each drive.