diff --git a/vdirsyncer/cli.py b/vdirsyncer/cli.py
index 277a3b3..17462b6 100644
--- a/vdirsyncer/cli.py
+++ b/vdirsyncer/cli.py
@@ -11,26 +11,31 @@ import os
 import ConfigParser
 from vdirsyncer.sync import sync_classes
 
+
 def _path(p):
     p = os.path.expanduser(p)
     p = os.path.abspath(p)
     return p
 
+
 def get_config_parser(env):
     fname = env.get('VDIRSYNCER_CONFIG', _path('~/.vdirsyncer/config'))
     c = ConfigParser.SafeConfigParser()
     c.read(fname)
     return dict((c, c.items(c)) for c in c.sections())
 
+
 def main():
     env = os.environ
     cfg = get_config_parser(env)
     _main(env, cfg)
 
+
 def _main(env, file_cfg):
     app = argvard.Argvard()
 
     sync = argvard.Command()
+
     @sync_command.main('[accounts...]')
     def sync_main(accounts=None):
         if accounts is None:
diff --git a/vdirsyncer/exceptions.py b/vdirsyncer/exceptions.py
index b9dc878..5172d0a 100644
--- a/vdirsyncer/exceptions.py
+++ b/vdirsyncer/exceptions.py
@@ -9,10 +9,12 @@
 
 
 class Error(Exception):
+
     '''Baseclass for all errors.'''
 
 
 class PreconditionFailed(Error):
+
     '''
       - The item doesn't exist although it should
       - The item exists although it shouldn't
@@ -24,16 +26,20 @@ class PreconditionFailed(Error):
 
 
 class NotFoundError(PreconditionFailed):
+
     '''Item not found'''
 
 
 class AlreadyExistingError(PreconditionFailed):
+
     '''Item already exists'''
 
 
 class WrongEtagError(PreconditionFailed):
+
     '''Wrong etag'''
 
 
 class StorageError(Error):
+
     '''Internal or initialization errors with storage.'''
diff --git a/vdirsyncer/storage/base.py b/vdirsyncer/storage/base.py
index 2caf0ad..e56a5c3 100644
--- a/vdirsyncer/storage/base.py
+++ b/vdirsyncer/storage/base.py
@@ -7,8 +7,11 @@
     :license: MIT, see LICENSE for more details.
 '''
 
+
 class Item(object):
+
     '''should-be-immutable wrapper class for VCALENDAR and VCARD'''
+
     def __init__(self, raw):
         self.raw = raw
         self._uid = None
@@ -23,15 +26,17 @@ class Item(object):
 
 
 class Storage(object):
+
     '''Superclass of all storages, mainly useful to summarize the interface to
     implement.
-    
+
     Terminology:
       - UID: Global identifier of the item, across storages.
       - HREF: Per-storage identifier of item, might be UID.
       - ETAG: Checksum of item, or something similar that changes when the object does
     '''
     fileext = '.txt'
+
     def __init__(self, item_class=Item):
         self.item_class = item_class
 
diff --git a/vdirsyncer/storage/caldav.py b/vdirsyncer/storage/caldav.py
index 8813520..1ab8ae0 100644
--- a/vdirsyncer/storage/caldav.py
+++ b/vdirsyncer/storage/caldav.py
@@ -17,10 +17,13 @@ import datetime
 
 CALDAV_DT_FORMAT = '%Y%m%dT%H%M%SZ'
 
+
 class CaldavStorage(Storage):
+
     '''hrefs are full URLs to items'''
     _session = None
     fileext = '.ics'
+
     def __init__(self, url, username='', password='', start_date=None,
                  end_date=None, verify=True, auth='basic',
                  useragent='vdirsyncer', _request_func=None, **kwargs):
@@ -106,7 +109,7 @@ class CaldavStorage(Storage):
             data = data.format(caldavfilter=caldavfilter)
         else:
             data = data.format(caldavfilter='')
-            
+
         response = self._request(
             'REPORT',
             '',
@@ -116,7 +119,8 @@ class CaldavStorage(Storage):
         response.raise_for_status()
         root = etree.XML(response.content)
         for element in root.iter('{DAV:}response'):
-            etag = element.find('{DAV:}propstat').find('{DAV:}prop').find('{DAV:}getetag').text
+            etag = element.find('{DAV:}propstat').find(
+                '{DAV:}prop').find('{DAV:}getetag').text
             href = self._simplify_href(element.find('{DAV:}href').text)
             yield href, etag
 
@@ -214,7 +218,7 @@ class CaldavStorage(Storage):
         if response.status_code == 412:
             raise exceptions.PreconditionFailed(response.content)
         response.raise_for_status()
-        
+
         etag = response.headers.get('etag', None)
         if not etag:
             obj2, etag = self.get(href)
diff --git a/vdirsyncer/storage/filesystem.py b/vdirsyncer/storage/filesystem.py
index 2728703..2a39222 100644
--- a/vdirsyncer/storage/filesystem.py
+++ b/vdirsyncer/storage/filesystem.py
@@ -11,10 +11,13 @@ import os
 from vdirsyncer.storage.base import Storage, Item
 import vdirsyncer.exceptions as exceptions
 
+
 class FilesystemStorage(Storage):
+
     '''Saves data in vdir collection
     mtime is etag
     filename without path is href'''
+
     def __init__(self, path, fileext, **kwargs):
         '''
         :param path: Absolute path to a *collection* inside a vdir.
diff --git a/vdirsyncer/storage/memory.py b/vdirsyncer/storage/memory.py
index 38db548..23c0882 100644
--- a/vdirsyncer/storage/memory.py
+++ b/vdirsyncer/storage/memory.py
@@ -8,13 +8,16 @@
 '''
 
 import datetime
-from vdirsyncer.storage.base import Item, Storage 
+from vdirsyncer.storage.base import Item, Storage
 import vdirsyncer.exceptions as exceptions
 
+
 class MemoryStorage(Storage):
+
     '''
     Saves data in RAM, only useful for testing.
     '''
+
     def __init__(self, **kwargs):
         self.items = {}  # href => (etag, object)
         super(MemoryStorage, self).__init__(**kwargs)
diff --git a/vdirsyncer/sync.py b/vdirsyncer/sync.py
index aff52e5..3752726 100644
--- a/vdirsyncer/sync.py
+++ b/vdirsyncer/sync.py
@@ -16,7 +16,7 @@
 
 def prepare_list(storage, href_to_uid):
     for href, etag in storage.list():
-        props = {'etag': etag} 
+        props = {'etag': etag}
         if href in href_to_uid:
             props['uid'] = href_to_uid[href]
         else:
@@ -49,9 +49,12 @@ def sync(storage_a, storage_b, status):
         modified by the function and should be passed to it at the next sync.
         If this is the first sync, an empty dictionary should be provided.
     '''
-    a_href_to_uid = dict((href_a, uid) for uid, (href_a, etag_a, href_b, etag_b) in status.iteritems())
-    b_href_to_uid = dict((href_b, uid) for uid, (href_a, etag_a, href_b, etag_b) in status.iteritems())
-    list_a = dict(prepare_list(storage_a, a_href_to_uid))  # href => {'etag': etag, 'obj': optional object, 'uid': uid}
+    a_href_to_uid = dict((href_a, uid)
+                         for uid, (href_a, etag_a, href_b, etag_b) in status.iteritems())
+    b_href_to_uid = dict((href_b, uid)
+                         for uid, (href_a, etag_a, href_b, etag_b) in status.iteritems())
+    # href => {'etag': etag, 'obj': optional object, 'uid': uid}
+    list_a = dict(prepare_list(storage_a, a_href_to_uid))
     list_b = dict(prepare_list(storage_b, b_href_to_uid))
     a_uid_to_href = dict((x['uid'], href) for href, x in list_a.iteritems())
     b_uid_to_href = dict((x['uid'], href) for href, x in list_b.iteritems())
@@ -59,7 +62,7 @@ def sync(storage_a, storage_b, status):
 
     actions, prefetch_from_a, prefetch_from_b = \
         get_actions(list_a, list_b, status, a_uid_to_href, b_uid_to_href)
-    
+
     prefetch(storage_a, list_a, prefetch_from_a)
     prefetch(storage_b, list_b, prefetch_from_b)
 
@@ -72,7 +75,7 @@ def sync(storage_a, storage_b, status):
     for action, uid, source, dest in actions:
         source_storage, source_list, source_uid_to_href = storages[source]
         dest_storage, dest_list, dest_uid_to_href = storages[dest]
-        
+
         if action in ('upload', 'update'):
             source_href = source_uid_to_href[uid]
             source_etag = source_list[source_href]['etag']
@@ -86,7 +89,8 @@ def sync(storage_a, storage_b, status):
                 dest_etag = dest_storage.update(dest_href, obj, old_etag)
             source_status = (source_href, source_etag)
             dest_status = (dest_href, dest_etag)
-            status[uid] = source_status + dest_status if source == 'a' else dest_status + source_status
+            status[uid] = source_status + dest_status if source == 'a' else \
+                dest_status + source_status
         elif action == 'delete':
             if dest is not None:
                 dest_href = dest_uid_to_href[uid]
@@ -94,6 +98,7 @@ def sync(storage_a, storage_b, status):
                 dest_storage.delete(dest_href, dest_etag)
             del status[uid]
 
+
 def get_actions(list_a, list_b, status, a_uid_to_href, b_uid_to_href):
     prefetch_from_a = []
     prefetch_from_b = []
@@ -110,19 +115,21 @@ def get_actions(list_a, list_b, status, a_uid_to_href, b_uid_to_href):
             if uid in uids_a and uid in uids_b:  # missing status
                 # TODO: might need some kind of diffing too?
                 if a['obj'].raw != b['obj'].raw:
-                    1/0
+                    1 / 0
                 status[uid] = (href_a, a['etag'], href_b, b['etag'])
-            elif uid in uids_a and uid not in uids_b:  # new item was created in a
+            # new item was created in a
+            elif uid in uids_a and uid not in uids_b:
                 prefetch_from_a.append(href_a)
                 actions.append(('upload', uid, 'a', 'b'))
-            elif uid not in uids_a and uid in uids_b:  # new item was created in b
+            # new item was created in b
+            elif uid not in uids_a and uid in uids_b:
                 prefetch_from_b.append(href_b)
                 actions.append(('upload', uid, 'b', 'a'))
         else:
             _, status_etag_a, _, status_etag_b = status[uid]
             if uid in uids_a and uid in uids_b:
                 if a['etag'] != status_etag_a and b['etag'] != status_etag_b:
-                    1/0  # conflict resolution TODO
+                    1 / 0  # conflict resolution TODO
                 elif a['etag'] != status_etag_a:  # item was updated in a
                     prefetch_from_a.append(href_a)
                     actions.append(('update', uid, 'a', 'b'))
@@ -135,6 +142,7 @@ def get_actions(list_a, list_b, status, a_uid_to_href, b_uid_to_href):
                 actions.append(('delete', uid, None, 'a'))
             elif uid not in uids_a and uid in uids_b:  # was deleted from a
                 actions.append(('delete', uid, None, 'b'))
-            elif uid not in uids_a and uid not in uids_b:  # was deleted from a and b
+            # was deleted from a and b
+            elif uid not in uids_a and uid not in uids_b:
                 actions.append(('delete', uid, None, None))
     return actions, prefetch_from_a, prefetch_from_b
diff --git a/vdirsyncer/tests/storage/__init__.py b/vdirsyncer/tests/storage/__init__.py
index 1db3991..cc9f54d 100644
--- a/vdirsyncer/tests/storage/__init__.py
+++ b/vdirsyncer/tests/storage/__init__.py
@@ -18,7 +18,9 @@ from vdirsyncer.storage.memory import MemoryStorage
 from vdirsyncer.storage.caldav import CaldavStorage
 import vdirsyncer.exceptions as exceptions
 
+
 class StorageTests(object):
+
     def _create_bogus_item(self, uid):
         return Item('''BEGIN:VCALENDAR
 VERSION:2.0
@@ -33,6 +35,7 @@ UID:{}
 END:VTODO
 END:VCALENDAR
 '''.format(uid))
+
     def _get_storage(self, **kwargs):
         raise NotImplementedError()
 
@@ -56,14 +59,17 @@ END:VCALENDAR
     def test_update_nonexisting(self):
         s = self._get_storage()
         item = self._create_bogus_item(1)
-        self.assertRaises(exceptions.PreconditionFailed, s.update, 'huehue', item, 123)
+        self.assertRaises(
+            exceptions.PreconditionFailed, s.update, 'huehue', item, 123)
 
     def test_wrong_etag(self):
         s = self._get_storage()
         obj = self._create_bogus_item(1)
         href, etag = s.upload(obj)
-        self.assertRaises(exceptions.PreconditionFailed, s.update, href, obj, 'lolnope')
-        self.assertRaises(exceptions.PreconditionFailed, s.delete, href, 'lolnope')
+        self.assertRaises(
+            exceptions.PreconditionFailed, s.update, href, obj, 'lolnope')
+        self.assertRaises(
+            exceptions.PreconditionFailed, s.delete, href, 'lolnope')
 
     def test_delete_nonexisting(self):
         s = self._get_storage()
diff --git a/vdirsyncer/tests/storage/test_caldav.py b/vdirsyncer/tests/storage/test_caldav.py
index a72fbca..2077d12 100644
--- a/vdirsyncer/tests/storage/test_caldav.py
+++ b/vdirsyncer/tests/storage/test_caldav.py
@@ -33,7 +33,9 @@ radicale.log.start()
 
 
 class Response(object):
+
     '''Fake API of requests module'''
+
     def __init__(self, x):
         self.x = x
         self.status_code = x.status_code
diff --git a/vdirsyncer/tests/storage/test_filesystem.py b/vdirsyncer/tests/storage/test_filesystem.py
index fe56d1a..7df2d7f 100644
--- a/vdirsyncer/tests/storage/test_filesystem.py
+++ b/vdirsyncer/tests/storage/test_filesystem.py
@@ -18,6 +18,7 @@ from . import StorageTests
 
 class FilesystemStorageTests(TestCase, StorageTests):
     tmpdir = None
+
     def _get_storage(self, **kwargs):
         path = self.tmpdir = tempfile.mkdtemp()
         return FilesystemStorage(path=path, fileext='.txt', **kwargs)
diff --git a/vdirsyncer/tests/storage/test_memory.py b/vdirsyncer/tests/storage/test_memory.py
index e02598a..9f7e12c 100644
--- a/vdirsyncer/tests/storage/test_memory.py
+++ b/vdirsyncer/tests/storage/test_memory.py
@@ -13,6 +13,8 @@ from unittest import TestCase
 from vdirsyncer.storage.memory import MemoryStorage
 from . import StorageTests
 
+
 class MemoryStorageTests(TestCase, StorageTests):
+
     def _get_storage(self, **kwargs):
         return MemoryStorage(**kwargs)
diff --git a/vdirsyncer/tests/test_sync.py b/vdirsyncer/tests/test_sync.py
index 732a01c..f73d19a 100644
--- a/vdirsyncer/tests/test_sync.py
+++ b/vdirsyncer/tests/test_sync.py
@@ -13,10 +13,13 @@ from vdirsyncer.storage.memory import MemoryStorage
 from vdirsyncer.sync import sync
 import vdirsyncer.exceptions as exceptions
 
+
 def empty_storage(x):
     return list(x.list()) == []
 
+
 class SyncTests(TestCase):
+
     def test_irrelevant_status(self):
         a = MemoryStorage()
         b = MemoryStorage()
@@ -101,7 +104,9 @@ class SyncTests(TestCase):
         item = Item('UID:1')
         a.upload(item)
         b.upload(item)
-        status = {'1': ('1.txt', a.get('1.txt')[1], '1.txt', b.get('1.txt')[1])}
+        status = {
+            '1': ('1.txt', a.get('1.txt')[1], '1.txt', b.get('1.txt')[1])
+        }
         old_status = dict(status)
         a.update = b.update = a.upload = b.upload = \
             lambda *a, **kw: self.fail('Method shouldn\'t have been called.')