- move inline "import" statements to use new "util.importlater()" construct. cuts

down on clutter, timeit says there's a teeny performance gain, at least where
the access is compared against attr.subattr.  these aren't super-critical
calls anyway
- slight inlining in _class_to_mapper

1 files changed, 4 insertions, 6 deletions

diff --git a/lib/sqlalchemy/orm/unitofwork.py b/lib/sqlalchemy/orm/unitofwork.py
index a9808e6ba..673591e8e 100644
--- a/lib/sqlalchemy/orm/unitofwork.py
+++ b/lib/sqlalchemy/orm/unitofwork.py
@@ -16,9 +16,7 @@ from sqlalchemy import util, topological
 from sqlalchemy.orm import attributes, interfaces
 from sqlalchemy.orm import util as mapperutil
 from sqlalchemy.orm.util import _state_mapper
-
-# Load lazily
-_state_session = None
+session = util.importlater("sqlalchemy.orm", "session")
 
 class UOWEventHandler(interfaces.AttributeExtension):
     """An event handler added to all relationship attributes which handles
@@ -34,7 +32,7 @@ class UOWEventHandler(interfaces.AttributeExtension):
         # process "save_update" cascade rules for when 
         # an instance is appended to the list of another instance
 
-        sess = _state_session(state)
+        sess = session._state_session(state)
         if sess:
             prop = _state_mapper(state).get_property(self.key)
             if prop.cascade.save_update and \
@@ -44,7 +42,7 @@ class UOWEventHandler(interfaces.AttributeExtension):
         return item
         
     def remove(self, state, item, initiator):
-        sess = _state_session(state)
+        sess = session._state_session(state)
         if sess:
             prop = _state_mapper(state).get_property(self.key)
             # expunge pending orphans
@@ -59,7 +57,7 @@ class UOWEventHandler(interfaces.AttributeExtension):
         if oldvalue is newvalue:
             return newvalue
 
-        sess = _state_session(state)
+        sess = session._state_session(state)
         if sess:
             prop = _state_mapper(state).get_property(self.key)
             if newvalue is not None and \