flake8 cleanup

2 files changed, 28 insertions, 24 deletions

diff --git a/lib/sqlalchemy/orm/base.py b/lib/sqlalchemy/orm/base.py
index a85f59f37..421d79630 100644
--- a/lib/sqlalchemy/orm/base.py
+++ b/lib/sqlalchemy/orm/base.py
@@ -144,38 +144,42 @@ _INSTRUMENTOR = ('mapper', 'instrumentor')
 EXT_CONTINUE = util.symbol('EXT_CONTINUE')
 EXT_STOP = util.symbol('EXT_STOP')
 
-ONETOMANY = util.symbol('ONETOMANY',
-                        """Indicates the one-to-many direction for a :func:`.relationship`.
+ONETOMANY = util.symbol(
+    'ONETOMANY',
+    """Indicates the one-to-many direction for a :func:`.relationship`.
 
-This symbol is typically used by the internals but may be exposed within
-certain API features.
+    This symbol is typically used by the internals but may be exposed within
+    certain API features.
 
-""")
+    """)
 
-MANYTOONE = util.symbol('MANYTOONE',
-                        """Indicates the many-to-one direction for a :func:`.relationship`.
+MANYTOONE = util.symbol(
+    'MANYTOONE',
+    """Indicates the many-to-one direction for a :func:`.relationship`.
 
-This symbol is typically used by the internals but may be exposed within
-certain API features.
+    This symbol is typically used by the internals but may be exposed within
+    certain API features.
 
-""")
+    """)
 
-MANYTOMANY = util.symbol('MANYTOMANY',
-                         """Indicates the many-to-many direction for a :func:`.relationship`.
+MANYTOMANY = util.symbol(
+    'MANYTOMANY',
+    """Indicates the many-to-many direction for a :func:`.relationship`.
 
-This symbol is typically used by the internals but may be exposed within
-certain API features.
+    This symbol is typically used by the internals but may be exposed within
+    certain API features.
 
-""")
+    """)
 
-NOT_EXTENSION = util.symbol('NOT_EXTENSION',
-                            """Symbol indicating an :class:`_InspectionAttr` that's
-   not part of sqlalchemy.ext.
+NOT_EXTENSION = util.symbol(
+    'NOT_EXTENSION',
+    """Symbol indicating an :class:`_InspectionAttr` that's
+    not part of sqlalchemy.ext.
 
-   Is assigned to the :attr:`._InspectionAttr.extension_type`
-   attibute.
+    Is assigned to the :attr:`._InspectionAttr.extension_type`
+    attibute.
 
-""")
+    """)
 
 _none_set = frozenset([None, NEVER_SET, PASSIVE_NO_RESULT])
 
diff --git a/lib/sqlalchemy/orm/interfaces.py b/lib/sqlalchemy/orm/interfaces.py
index 9bc1c3dd0..d95b78f24 100644
--- a/lib/sqlalchemy/orm/interfaces.py
+++ b/lib/sqlalchemy/orm/interfaces.py
@@ -19,15 +19,15 @@ classes within should be considered mostly private.
 
 from __future__ import absolute_import
 
-from .. import exc as sa_exc, util, inspect
+from .. import util
 from ..sql import operators
-from collections import deque
 from .base import (ONETOMANY, MANYTOONE, MANYTOMANY,
                    EXT_CONTINUE, EXT_STOP, NOT_EXTENSION)
 from .base import _InspectionAttr, _MappedAttribute
-from .path_registry import PathRegistry
 import collections
 
+# imported later
+MapperExtension = SessionExtension = AttributeExtension = None
 
 __all__ = (
     'AttributeExtension',