Issue #18200: Update the stdlib (except tests) to use
ModuleNotFoundError.
diff --git a/Lib/pdb.py b/Lib/pdb.py
index e5596e5..d964f98 100755
--- a/Lib/pdb.py
+++ b/Lib/pdb.py
@@ -158,7 +158,7 @@
             import readline
             # remove some common file name delimiters
             readline.set_completer_delims(' \t\n`@#$%^&*()=+[{]}\\|;:\'",<>?')
-        except ImportError:
+        except ModuleNotFoundError:
             pass
         self.allow_kbdint = False
         self.nosigint = nosigint