From 7f4fe75c49d9bf5773c1958eab75dd1d0be10f72 2023-08-28 08:31:58
From: Matthias Bussonnier <bussonniermatthias@gmail.com>
Date: 2023-08-28 08:31:58
Subject: [PATCH] Fix clearing output references with `%reset out` (#14133)

This should fix #14129. Namely the second reference to the output is
stored in `user_ns_hidden`. That was already cleared during hard
`%reset` but was not cleared when using `%reset out`. Manual
`gc.collect()` is still required.
---

diff --git a/IPython/core/displayhook.py b/IPython/core/displayhook.py
index aba4f90..b411f11 100644
--- a/IPython/core/displayhook.py
+++ b/IPython/core/displayhook.py
@@ -297,8 +297,13 @@ class DisplayHook(Configurable):
         for n in range(1,self.prompt_count + 1):
             key = '_'+repr(n)
             try:
+                del self.shell.user_ns_hidden[key]
+            except KeyError:
+                pass
+            try:
                 del self.shell.user_ns[key]
-            except: pass
+            except KeyError:
+                pass
         # In some embedded circumstances, the user_ns doesn't have the
         # '_oh' key set up.
         oh = self.shell.user_ns.get('_oh', None)