conditional typing ext

lib/python/pyflyby/_importclns.py

@@ -4,7 +4,7 @@
 
 from __future__ import annotations
 
-
+import sys
 
 from   collections              import defaultdict
 from   functools                import total_ordering
@@ -21,7 +21,10 @@
 from   typing                   import (ClassVar, Dict, FrozenSet, List,
                                         Sequence, Union)
 
-from typing_extensions          import Self
+if sys.version_info < (3, 12):
+    from typing_extensions          import Self
+else:
+    from typing import Self
 
 
 class NoSuchImportError(ValueError):

lib/python/pyflyby/_importdb.py

@@ -7,9 +7,10 @@
 from   collections              import defaultdict
 import os
 import re
+import sys
 
 from   typing                   import Dict, Any, Tuple
-from   typing_extensions        import Self
+
 
 from   pyflyby._file            import Filename, expand_py_files_from_args, UnsafeFilenameError
 from   pyflyby._idents          import dotted_prefixes
@@ -19,6 +20,10 @@
 from   pyflyby._parse           import PythonBlock
 from   pyflyby._util            import cached_attribute, memoize, stable_unique
 
+if sys.version_info = (3,12):
+    from   typing_extensions        import Self
+else:
+    from typing import self
 
 
 @memoize