Fixed SQL_IN when getquoted() is called without prepare()

lib/extensions.py

@@ -116,20 +116,21 @@ def register_adapter(typ, callable):
 # The SQL_IN class is the official adapter for tuples starting from 2.0.6.
 class SQL_IN(object):
     """Adapt any iterable to an SQL quotable object."""
-    
     def __init__(self, seq):
         self._seq = seq
+        self._conn = None
 
     def prepare(self, conn):
         self._conn = conn
-    
+
     def getquoted(self):
         # this is the important line: note how every object in the
         # list is adapted and then how getquoted() is called on it
         pobjs = [adapt(o) for o in self._seq]
-        for obj in pobjs:
-            if hasattr(obj, 'prepare'):
-                obj.prepare(self._conn)
+        if self._conn is not None:
+            for obj in pobjs:
+                if hasattr(obj, 'prepare'):
+                    obj.prepare(self._conn)
         qobjs = [o.getquoted() for o in pobjs]
         return b('(') + b(', ').join(qobjs) + b(')')