diff --git a/src/calibre/devices/usbms/device.py b/src/calibre/devices/usbms/device.py
index 0af8b8071d..0fe7fd4aca 100644
--- a/src/calibre/devices/usbms/device.py
+++ b/src/calibre/devices/usbms/device.py
@@ -89,7 +89,6 @@ class Device(DeviceConfig, DevicePlugin):
     STORAGE_CARD_VOLUME_LABEL = ''
     STORAGE_CARD2_VOLUME_LABEL = None
 
-
     EBOOK_DIR_MAIN = ''
     EBOOK_DIR_CARD_A = ''
     EBOOK_DIR_CARD_B = ''
@@ -110,7 +109,7 @@ class Device(DeviceConfig, DevicePlugin):
         self._main_prefix = self._card_a_prefix = self._card_b_prefix = None
         try:
             self.detected_device = USBDevice(detected_device)
-        except: # On windows detected_device is None
+        except:  # On windows detected_device is None
             self.detected_device = None
         self.set_progress_reporter(report_progress)
 
@@ -138,7 +137,8 @@ class Device(DeviceConfig, DevicePlugin):
                 time.sleep(3)
                 sectors_per_cluster, bytes_per_sector, free_clusters, total_clusters = \
                     win32file.GetDiskFreeSpace(prefix)
-            else: raise
+            else:
+                raise
         mult = sectors_per_cluster * bytes_per_sector
         return total_clusters * mult, free_clusters * mult
 
@@ -254,7 +254,6 @@ class Device(DeviceConfig, DevicePlugin):
                 pass
             return False
 
-
         for drive, pnp_id in win_pnp_drives().items():
             if self.windows_match_device(pnp_id, 'WINDOWS_CARD_A_MEM') and \
                     not drives.get('carda', False):
@@ -315,12 +314,11 @@ class Device(DeviceConfig, DevicePlugin):
             try:
                 return subprocess.Popen(cmd,
                                     stdout=subprocess.PIPE).communicate()[0]
-            except IOError: # Probably an interrupted system call
+            except IOError:  # Probably an interrupted system call
                 if i == 2:
                     raise
             time.sleep(2)
 
-
     def osx_sort_names(self, names):
         return names
 
@@ -373,7 +371,7 @@ class Device(DeviceConfig, DevicePlugin):
             try:
                 return subprocess.Popen('mount',
                                     stdout=subprocess.PIPE).communicate()[0]
-            except IOError: # Probably an interrupted system call
+            except IOError:  # Probably an interrupted system call
                 if i == 2:
                     raise
             time.sleep(2)
@@ -450,9 +448,11 @@ class Device(DeviceConfig, DevicePlugin):
         for i in range(3):
             try:
                 drives = self._osx_bsd_names()
-                if len(drives) > 1: return drives
+                if len(drives) > 1:
+                    return drives
             except:
-                if i == 2: raise
+                if i == 2:
+                    raise
             time.sleep(3)
         return drives
 
@@ -621,19 +621,22 @@ class Device(DeviceConfig, DevicePlugin):
         if mp is None:
             raise DeviceError(
             _('Unable to mount main memory (Error code: %d)')%ret)
-        if not mp.endswith('/'): mp += '/'
+        if not mp.endswith('/'):
+            mp += '/'
         self._linux_mount_map[main] = mp
         self._main_prefix = mp
         self._linux_main_device_node = main
         cards = [(carda, '_card_a_prefix', 'carda'),
                  (cardb, '_card_b_prefix', 'cardb')]
         for card, prefix, typ in cards:
-            if card is None: continue
+            if card is None:
+                continue
             mp, ret = mount(card, typ)
             if mp is None:
                 print >>sys.stderr, 'Unable to mount card (Error code: %d)'%ret
             else:
-                if not mp.endswith('/'): mp += '/'
+                if not mp.endswith('/'):
+                    mp += '/'
                 setattr(self, prefix, mp)
                 self._linux_mount_map[card] = mp
 
@@ -679,7 +682,6 @@ class Device(DeviceConfig, DevicePlugin):
             self._card_a_prefix = self._card_b_prefix
             self._card_b_prefix = None
 
-
 # ------------------------------------------------------
 #
 #  open for FreeBSD
@@ -731,7 +733,8 @@ class Device(DeviceConfig, DevicePlugin):
                                     if vdevif.GetProperty('volume.fsusage') != 'filesystem':
                                         continue
                                     volif = dbus.Interface(bus.get_object('org.freedesktop.Hal', vpath), 'org.freedesktop.Hal.Device.Volume')
-                                    pdevif = dbus.Interface(bus.get_object('org.freedesktop.Hal', vdevif.GetProperty('info.parent')), 'org.freedesktop.Hal.Device')
+                                    pdevif = dbus.Interface(bus.get_object('org.freedesktop.Hal', vdevif.GetProperty('info.parent')),
+                                                            'org.freedesktop.Hal.Device')
                                     vol = {'node': pdevif.GetProperty('block.device'),
                                             'dev': vdevif,
                                             'vol': volif,
@@ -1054,8 +1057,8 @@ class Device(DeviceConfig, DevicePlugin):
         filepath = create_upload_path(mdata, fname, self.save_template(), self.sanitize_callback,
                 prefix_path=os.path.abspath(path),
                 maxlen=self.MAX_PATH_LEN,
-                use_subdirs = self.SUPPORTS_SUB_DIRS and settings.use_subdirs,
-                news_in_folder = self.NEWS_IN_FOLDER,
+                use_subdirs=self.SUPPORTS_SUB_DIRS and settings.use_subdirs,
+                news_in_folder=self.NEWS_IN_FOLDER,
                 filename_callback=self.filename_callback,
                 sanitize_path_components=self.sanitize_path_components
                 )
@@ -1067,4 +1070,4 @@ class Device(DeviceConfig, DevicePlugin):
         return filepath
 
     def create_annotations_path(self, mdata, device_path=None):
-         return self.create_upload_path(os.path.abspath('/<storage>'), mdata, 'x.bookmark', create_dirs=False)
+        return self.create_upload_path(os.path.abspath('/<storage>'), mdata, 'x.bookmark', create_dirs=False)