You can use Udisks via dbus directly in python.
import dbus
bus = dbus.SystemBus()
ud_manager_obj = bus.get_object("org.freedesktop.UDisks", "/org/freedesktop/UDisks")
ud_manager = dbus.Interface(ud_manager_obj, 'org.freedesktop.UDisks')
for dev in ud_manager.EnumerateDevices():
device_obj = bus.get_object("org.freedesktop.UDisks", dev)
device_props = dbus.Interface(device_obj, dbus.PROPERTIES_IFACE)
print device_props.Get('org.freedesktop.UDisks.Device', "DriveVendor")
print device_props.Get('org.freedesktop.UDisks.Device', "DeviceMountPaths")
print device_props.Get('org.freedesktop.UDisks.Device', "DriveSerial")
print device_props.Get('org.freedesktop.UDisks.Device', "PartitionSize")
The full list of properties available is here http://hal.freedesktop.org/docs/udisks/Device.html