Rename enginefacade.async to enginefacade.async_

Python 3.7 now makes "async" a keyword, so deprecate the
"async" name and replace with "async_".  Additionally,
use attribute name access only in order to implement and
test "async" as it won't work under Python 3.7.

Closes-Bug: #1775866
Change-Id: Ifb2c59c2cfbd615b04570b31fcfe868f4ffea3c6

1 files changed, 13 insertions, 1 deletions

diff --git a/oslo_db/sqlalchemy/enginefacade.py b/oslo_db/sqlalchemy/enginefacade.py
index 2b9f81e..481e166 100644
--- a/oslo_db/sqlalchemy/enginefacade.py
+++ b/oslo_db/sqlalchemy/enginefacade.py
@@ -17,6 +17,7 @@ import operator
 import threading
 import warnings
 
+import debtcollector.moves
 import debtcollector.removals
 import debtcollector.renames
 from oslo_config import cfg
@@ -965,7 +966,7 @@ class _TransactionContextManager(object):
         return self._clone(connection=True)
 
     @property
-    def async(self):
+    def async_(self):
         """Modifier to set a READER operation to ASYNC_READER."""
 
         if self._mode is _WRITER:
@@ -1049,6 +1050,17 @@ class _TransactionContextManager(object):
                 transaction_contexts_by_thread.current = restore
 
 
+@property
+@debtcollector.moves.moved_property("async_")
+def async_compat(self):
+    return self.async_
+
+setattr(
+    _TransactionContextManager,
+    "async", async_compat
+)
+
+
 def _context_descriptor(attr=None):
     getter = operator.attrgetter(attr)