diff --git a/pymongo/__init__.py b/pymongo/__init__.py
index 4eff1e1a7..cd5221870 100644
--- a/pymongo/__init__.py
+++ b/pymongo/__init__.py
@@ -45,6 +45,7 @@ version = "1.6+"
 Connection = PyMongo_Connection
 """Alias for :class:`pymongo.connection.Connection`."""
 
+
 def has_c():
     """Is the C extension installed?
 
diff --git a/pymongo/binary.py b/pymongo/binary.py
index c70b950ef..d014f6bc7 100644
--- a/pymongo/binary.py
+++ b/pymongo/binary.py
@@ -50,6 +50,7 @@ USER_DEFINED_SUBTYPE = 128
 .. versionadded:: 1.5
 """
 
+
 class Binary(str):
     """Representation of binary data to be stored in or retrieved from MongoDB.
 
diff --git a/pymongo/bson.py b/pymongo/bson.py
index de04e4ab4..40cccb5cf 100644
--- a/pymongo/bson.py
+++ b/pymongo/bson.py
@@ -195,17 +195,17 @@ _element_getter = {
     "\x03": _get_object,
     "\x04": _get_array,
     "\x05": _get_binary,
-    "\x06": _get_null, # undefined
+    "\x06": _get_null,  # undefined
     "\x07": _get_oid,
     "\x08": _get_boolean,
     "\x09": _get_date,
     "\x0A": _get_null,
     "\x0B": _get_regex,
     "\x0C": _get_ref,
-    "\x0D": _get_string, # code
-    "\x0E": _get_string, # symbol
+    "\x0D": _get_string,  # code
+    "\x0E": _get_string,  # symbol
     "\x0F": _get_code_w_scope,
-    "\x10": _get_int, # number_int
+    "\x10": _get_int,  # number_int
     "\x11": _get_timestamp,
     "\x12": _get_long,
     "\xFF": lambda x, y: (MinKey(), x),
@@ -297,9 +297,9 @@ def _element_to_bson(key, value, check_keys):
         return "\x08" + name + "\x00"
     if isinstance(value, (int, long)):
         # TODO this is a really ugly way to check for this...
-        if value > 2**64 / 2 - 1 or value < -2**64 / 2:
+        if value > 2 ** 64 / 2 - 1 or value < -2 ** 64 / 2:
             raise OverflowError("MongoDB can only handle up to 8-byte ints")
-        if value > 2**32 / 2 - 1 or value < -2**32 / 2:
+        if value > 2 ** 32 / 2 - 1 or value < -2 ** 32 / 2:
             return "\x12" + name + struct.pack("<q", value)
         return "\x10" + name + struct.pack("<i", value)
     if isinstance(value, datetime.datetime):
@@ -355,8 +355,8 @@ def _dict_to_bson(dict, check_keys, top_level=True):
 
     length = len(elements) + 5
     if length > 4 * 1024 * 1024:
-        raise InvalidDocument("document too large - BSON documents are limited "
-                              "to 4 MB")
+        raise InvalidDocument("document too large - BSON documents are"
+                              "limited to 4 MB")
     return struct.pack("<i", length) + elements + "\x00"
 if _use_c:
     _dict_to_bson = _cbson._dict_to_bson
diff --git a/pymongo/code.py b/pymongo/code.py
index f0ec16d69..3d3392808 100644
--- a/pymongo/code.py
+++ b/pymongo/code.py
@@ -15,6 +15,7 @@
 """Tools for representing JavaScript code to be evaluated by MongoDB.
 """
 
+
 class Code(str):
     """JavaScript code to be evaluated by MongoDB.
 
diff --git a/pymongo/collection.py b/pymongo/collection.py
index 0fc319d6c..ebf0c4f08 100644
--- a/pymongo/collection.py
+++ b/pymongo/collection.py
@@ -481,7 +481,8 @@ class Collection(object):
         """
         return self.find().count()
 
-    def create_index(self, key_or_list, deprecated_unique=None, ttl=300, **kwargs):
+    def create_index(self, key_or_list, deprecated_unique=None,
+                     ttl=300, **kwargs):
         """Creates an index on this collection.
 
         Takes either a single key or a list of (key, direction) pairs.
@@ -564,7 +565,8 @@ class Collection(object):
                                               check_keys=False)
         return name
 
-    def ensure_index(self, key_or_list, deprecated_unique=None, ttl=300, **kwargs):
+    def ensure_index(self, key_or_list, deprecated_unique=None,
+                     ttl=300, **kwargs):
         """Ensures that an index exists on this collection.
 
         Takes either a single key or a list of (key, direction) pairs.
@@ -631,7 +633,8 @@ class Collection(object):
 
         if self.__database.connection._cache_index(self.__database.name,
                                                    self.__name, name, ttl):
-            return self.create_index(key_or_list, deprecated_unique, ttl, **kwargs)
+            return self.create_index(key_or_list, deprecated_unique,
+                                     ttl, **kwargs)
         return None
 
     def drop_indexes(self):
diff --git a/pymongo/connection.py b/pymongo/connection.py
index e715f1256..ab3938bbe 100644
--- a/pymongo/connection.py
+++ b/pymongo/connection.py
@@ -94,7 +94,7 @@ class Pool(threading.local):
         self.sock = None
 
 
-class Connection(object): # TODO support auth for pooling
+class Connection(object):  # TODO support auth for pooling
     """Connection to MongoDB.
     """
 
@@ -189,7 +189,8 @@ class Connection(object): # TODO support auth for pooling
         i = source.find(sub)
         if i == -1:
             return (source, None)
-        return (source[:i], source[i+len(sub):])
+
+        return (source[:i], source[i + len(sub):])
 
     @staticmethod
     def _parse_uri(uri):
@@ -198,7 +199,8 @@ class Connection(object): # TODO support auth for pooling
         if uri.startswith("mongodb://"):
             uri = uri[len("mongodb://"):]
         elif "://" in uri:
-            raise InvalidURI("Invalid uri scheme: %s" % Connection.__partition(uri, "://")[0])
+            raise InvalidURI("Invalid uri scheme: %s"
+                             % Connection.__partition(uri, "://")[0])
 
         (hosts, database) = Connection.__partition(uri, "/")
 
@@ -211,7 +213,8 @@ class Connection(object): # TODO support auth for pooling
             (auth, hosts) = Connection.__partition(hosts, "@")
 
             if ":" not in auth:
-                raise InvalidURI("auth must be specified as 'username:password@'")
+                raise InvalidURI("auth must be specified as "
+                                 "'username:password@'")
             (username, password) = Connection.__partition(auth, ":")
 
         host_list = []
@@ -441,7 +444,7 @@ class Connection(object): # TODO support auth for pooling
                         self.__port = port
                         return
                 except socket.error, e:
-                    sock_error=True
+                    sock_error = True
             finally:
                 if sock is not None:
                     sock.close()
@@ -499,9 +502,10 @@ class Connection(object): # TODO support auth for pooling
         """Set this connection's cursor manager.
 
         Raises :class:`TypeError` if `manager_class` is not a subclass of
-        :class:`~pymongo.cursor_manager.CursorManager`. A cursor manager handles
-        closing cursors. Different managers can implement different policies in
-        terms of when to actually kill a cursor that has been closed.
+        :class:`~pymongo.cursor_manager.CursorManager`. A cursor manager
+        handles closing cursors. Different managers can implement different
+        policies in terms of when to actually kill a cursor that has
+        been closed.
 
         :Parameters:
           - `manager_class`: cursor manager to use
@@ -562,7 +566,8 @@ class Connection(object): # TODO support auth for pooling
             # lastError) and raise OperationFailure if it is an error
             # response.
             if with_last_error:
-                response = self.__receive_message_on_socket(1, request_id, sock)
+                response = self.__receive_message_on_socket(1, request_id,
+                                                            sock)
                 return self.__check_response_to_last_error(response)
             return None
         except (ConnectionFailure, socket.error), e:
diff --git a/pymongo/cursor.py b/pymongo/cursor.py
index aa9c3debb..3d4d90eef 100644
--- a/pymongo/cursor.py
+++ b/pymongo/cursor.py
@@ -25,8 +25,7 @@ _QUERY_OPTIONS = {
     "tailable_cursor": 2,
     "slave_okay": 4,
     "oplog_replay": 8,
-    "no_timeout": 16
-}
+    "no_timeout": 16}
 
 
 # TODO might be cool to be able to do find().include("foo") or
@@ -263,13 +262,15 @@ class Cursor(object):
             skip = 0
             if index.start is not None:
                 if index.start < 0:
-                    raise IndexError("Cursor instances do not support negative indices")
+                    raise IndexError("Cursor instances do not support"
+                                     "negative indices")
                 skip = index.start
 
             if index.stop is not None:
                 limit = index.stop - skip
                 if limit <= 0:
-                    raise IndexError("stop index must be greater than start index for slice %r" % index)
+                    raise IndexError("stop index must be greater than start"
+                                     "index for slice %r" % index)
             else:
                 limit = 0
 
@@ -279,14 +280,16 @@ class Cursor(object):
 
         if isinstance(index, (int, long)):
             if index < 0:
-                raise IndexError("Cursor instances do not support negative indices")
+                raise IndexError("Cursor instances do not support negative"
+                                 "indices")
             clone = self.clone()
             clone.skip(index + self.__skip)
-            clone.limit(-1) # use a hard limit
+            clone.limit(-1)  # use a hard limit
             for doc in clone:
                 return doc
             raise IndexError("no such item for Cursor instance")
-        raise TypeError("index %r cannot be applied to Cursor instances" % index)
+        raise TypeError("index %r cannot be applied to Cursor "
+                        "instances" % index)
 
     def max_scan(self, max_scan):
         """Limit the number of documents to scan when performing the query.
diff --git a/pymongo/database.py b/pymongo/database.py
index a4ed2b86e..ef10d666b 100644
--- a/pymongo/database.py
+++ b/pymongo/database.py
@@ -82,8 +82,8 @@ class Database(object):
           - `manipulator`: the manipulator to add
         """
         def method_overwritten(instance, method):
-            return getattr(instance, method) != getattr(super(instance.__class__, instance), method)
-
+            return getattr(instance, method) != \
+                getattr(super(instance.__class__, instance), method)
 
         if manipulator.will_copy():
             if method_overwritten(manipulator, "transform_incoming"):
@@ -440,9 +440,10 @@ class Database(object):
 
         .. versionadded:: 1.4
         """
+        pwd = helpers._password_digest(name, password)
         self.system.users.update({"user": name},
                                  {"user": name,
-                                  "pwd": helpers._password_digest(name, password)},
+                                  "pwd": pwd},
                                  upsert=True, safe=True)
 
     def remove_user(self, name):
@@ -509,7 +510,8 @@ class Database(object):
         nonce = self.command("getnonce")["nonce"]
         key = helpers._auth_key(nonce, name, password)
         try:
-            self.command("authenticate", user=unicode(name), nonce=nonce, key=key)
+            self.command("authenticate", user=unicode(name),
+                         nonce=nonce, key=key)
             return True
         except OperationFailure:
             return False
@@ -525,9 +527,9 @@ class Database(object):
         """Dereference a DBRef, getting the SON object it points to.
 
         Raises TypeError if `dbref` is not an instance of DBRef. Returns a SON
-        object or None if the reference does not point to a valid object. Raises
-        ValueError if `dbref` has a database specified that is different from
-        the current database.
+        object or None if the reference does not point to a valid object.
+        Raises ValueError if `dbref` has a database specified that is different
+        from the current database.
 
         :Parameters:
           - `dbref`: the reference
diff --git a/pymongo/errors.py b/pymongo/errors.py
index ca5bdce18..88b6522fd 100644
--- a/pymongo/errors.py
+++ b/pymongo/errors.py
@@ -14,6 +14,7 @@
 
 """Exceptions raised by PyMongo."""
 
+
 class PyMongoError(Exception):
     """Base class for all PyMongo exceptions.
 
diff --git a/pymongo/helpers.py b/pymongo/helpers.py
index 19fa2009b..f6fd501bf 100644
--- a/pymongo/helpers.py
+++ b/pymongo/helpers.py
@@ -12,12 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""Little bits and pieces used by the driver that don't really fit elsewhere."""
+"""Bits and pieces used by the driver that don't really fit elsewhere."""
 
 try:
     import hashlib
     _md5func = hashlib.md5
-except: # for Python < 2.5
+except:  # for Python < 2.5
     import md5
     _md5func = md5.new
 import struct
@@ -28,6 +28,7 @@ from pymongo.errors import (OperationFailure,
                             AutoReconnect)
 from pymongo.son import SON
 
+
 def _index_list(key_or_list, direction=None):
     """Helper to generate a list of (key, direction) pairs.
 
diff --git a/pymongo/json_util.py b/pymongo/json_util.py
index 6c61187b3..6426fae3b 100644
--- a/pymongo/json_util.py
+++ b/pymongo/json_util.py
@@ -55,6 +55,7 @@ from pymongo.objectid import ObjectId
 # TODO share this with bson.py?
 _RE_TYPE = type(re.compile("foo"))
 
+
 def object_hook(dct):
     if "$oid" in dct:
         return ObjectId(str(dct["$oid"]))
@@ -71,6 +72,7 @@ def object_hook(dct):
         return re.compile(dct["$regex"], flags)
     return dct
 
+
 def default(obj):
     if isinstance(obj, ObjectId):
         return {"$oid": str(obj)}
diff --git a/pymongo/master_slave_connection.py b/pymongo/master_slave_connection.py
index 478e03b47..e33307883 100644
--- a/pymongo/master_slave_connection.py
+++ b/pymongo/master_slave_connection.py
@@ -138,9 +138,9 @@ class MasterSlaveConnection(object):
             return (-1, self.__master._send_message_with_response(message,
                                                                   _sock))
 
-        return (connection_id,
-                self.__slaves[connection_id]._send_message_with_response(message,
-                                                                         _sock))
+        slaves = self.__slaves[connection_id]
+        return (connection_id, slaves._send_message_with_response(message,
+                                                                  _sock))
 
     def start_request(self):
         """Start a "request".
diff --git a/pymongo/message.py b/pymongo/message.py
index c7c9607b5..6d6cfbfec 100644
--- a/pymongo/message.py
+++ b/pymongo/message.py
@@ -48,10 +48,10 @@ def __pack_message(operation, data):
 
     Returns the resultant message string.
     """
-    request_id = random.randint(-2**31 - 1, 2**31)
+    request_id = random.randint(-2 ** 31 - 1, 2 ** 31)
     message = struct.pack("<i", 16 + len(data))
     message += struct.pack("<i", request_id)
-    message += __ZERO # responseTo
+    message += __ZERO  # responseTo
     message += struct.pack("<i", operation)
     return (request_id, message + data)
 
diff --git a/pymongo/objectid.py b/pymongo/objectid.py
index 75a4a4808..8c73d542c 100644
--- a/pymongo/objectid.py
+++ b/pymongo/objectid.py
@@ -21,7 +21,7 @@ import datetime
 try:
     import hashlib
     _md5func = hashlib.md5
-except ImportError: # for Python < 2.5
+except ImportError:  # for Python < 2.5
     import md5
     _md5func = md5.new
 import os
@@ -64,8 +64,8 @@ class ObjectId(object):
             hex string)
 
         .. versionadded:: 1.2.1
-           The `oid` parameter can be a ``unicode`` instance (that contains only
-           hexadecimal digits).
+           The `oid` parameter can be a ``unicode`` instance (that contains
+           only hexadecimal digits).
 
         .. mongodoc:: objectids
         """
@@ -193,5 +193,3 @@ class ObjectId(object):
         .. versionadded:: 1.1
         """
         return hash(self.__id)
-
-
diff --git a/pymongo/timestamp.py b/pymongo/timestamp.py
index 182af8ea9..c24af19a3 100644
--- a/pymongo/timestamp.py
+++ b/pymongo/timestamp.py
@@ -20,6 +20,7 @@
 import calendar
 import datetime
 
+
 class Timestamp(object):
     """MongoDB internal timestamps used in the opLog.
     """
@@ -53,10 +54,10 @@ class Timestamp(object):
             raise TypeError("time must be an instance of int")
         if not isinstance(inc, int):
             raise TypeError("inc must be an instance of int")
-        if not 0 <= time < 2**32:
+        if not 0 <= time < 2 ** 32:
             raise ValueError("time must be contained in [0, 2**32)")
-        if not 0 <= inc < 2**32:
-            raise ValueError("inc must be contained in [0, 2**32), not %r" % inc)
+        if not 0 <= inc < 2 ** 32:
+            raise ValueError("inc must be contained in [0, 2**32)")
 
         self.__time = time
         self.__inc = inc