- add "force_nocheck" as a way to turn on unicode=force without even

doing the isinstance() check - currently used only by psycopg2 + native enum + py2k.
- didn't realize psycopg2 had UNICODEARRAY extension all this time; replace _PGArray
with just using UNICODEARRAY instead.
- replace unnecessary/inconsistent __import__ in _isolation_lookup.

1 files changed, 7 insertions, 2 deletions

diff --git a/lib/sqlalchemy/sql/sqltypes.py b/lib/sqlalchemy/sql/sqltypes.py
index 1c475a28b..6ed20084b 100644
--- a/lib/sqlalchemy/sql/sqltypes.py
+++ b/lib/sqlalchemy/sql/sqltypes.py
@@ -192,13 +192,18 @@ class String(Concatenable, TypeEngine):
         wants_unicode = self.convert_unicode or dialect.convert_unicode
         needs_convert = wants_unicode and \
                         (dialect.returns_unicode_strings is not True or
-                        self.convert_unicode == 'force')
+                        self.convert_unicode in ('force', 'force_nocheck'))
+        needs_isinstance = (
+                                needs_convert and
+                                dialect.returns_unicode_strings and
+                                self.convert_unicode != 'force_nocheck'
+                            )
 
         if needs_convert:
             to_unicode = processors.to_unicode_processor_factory(
                                     dialect.encoding, self.unicode_error)
 
-            if dialect.returns_unicode_strings:
+            if needs_isinstance:
                 # we wouldn't be here unless convert_unicode='force'
                 # was specified, or the driver has erratic unicode-returning
                 # habits.  since we will be getting back unicode