first model in postgresql base

Lib/site-packages/psycopg2/compat.py

@@ -0,0 +1,19 @@
+import sys
+
+__all__ = ['string_types', 'text_type', 'lru_cache']
+
+if sys.version_info[0] == 2:
+    # Python 2
+    PY2 = True
+    PY3 = False
+    string_types = basestring,
+    text_type = unicode
+    from ._lru_cache import lru_cache
+
+else:
+    # Python 3
+    PY2 = False
+    PY3 = True
+    string_types = str,
+    text_type = str
+    from functools import lru_cache