From b05bab2925772d24b3b655227e9088541c2f2e33 Mon Sep 17 00:00:00 2001
From: "Thomas J. Fan" <thomasjpfan@gmail.com>
Date: Thu, 25 Feb 2021 16:03:18 -0500
Subject: [PATCH 1/3] ENH Adds final_estimator in html repr for Stacking

---
 sklearn/ensemble/_stacking.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/sklearn/ensemble/_stacking.py b/sklearn/ensemble/_stacking.py
index 303015cc9f751..3fe796a7debd5 100644
--- a/sklearn/ensemble/_stacking.py
+++ b/sklearn/ensemble/_stacking.py
@@ -250,9 +250,11 @@ def _sk_visual_block_(self, final_estimator):
         names, estimators = zip(*self.estimators)
         parallel = _VisualBlock('parallel', estimators, names=names,
                                 dash_wrapped=False)
-        serial = _VisualBlock('serial', (parallel, final_estimator),
-                              dash_wrapped=False)
-        return _VisualBlock('serial', [serial])
+        final_block = _VisualBlock('parallel', [final_estimator],
+                                   names=['final_estimator'],
+                                   dash_wrapped=False)
+        return _VisualBlock('serial', (parallel, final_block),
+                            dash_wrapped=False)
 
 
 class StackingClassifier(ClassifierMixin, _BaseStacking):

From 7ab537d6531ea7340f3314f9a2374301f16c964c Mon Sep 17 00:00:00 2001
From: "Thomas J. Fan" <thomasjpfan@gmail.com>
Date: Fri, 26 Feb 2021 09:35:52 -0500
Subject: [PATCH 2/3] DOC Adds comment

---
 sklearn/ensemble/_stacking.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sklearn/ensemble/_stacking.py b/sklearn/ensemble/_stacking.py
index 3fe796a7debd5..4f5800580f8d6 100644
--- a/sklearn/ensemble/_stacking.py
+++ b/sklearn/ensemble/_stacking.py
@@ -250,6 +250,9 @@ def _sk_visual_block_(self, final_estimator):
         names, estimators = zip(*self.estimators)
         parallel = _VisualBlock('parallel', estimators, names=names,
                                 dash_wrapped=False)
+
+        # final estimator is wrapped in a parallel block to show the label:
+        # 'final_estimator' in the html repr
         final_block = _VisualBlock('parallel', [final_estimator],
                                    names=['final_estimator'],
                                    dash_wrapped=False)

From 2fda9541a917805b87b8233d6f877cfcba2bc2bc Mon Sep 17 00:00:00 2001
From: Guillaume Lemaitre <g.lemaitre58@gmail.com>
Date: Fri, 9 Apr 2021 11:18:58 +0200
Subject: [PATCH 3/3] DOC add entry whats new

---
 doc/whats_new/v1.0.rst | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/doc/whats_new/v1.0.rst b/doc/whats_new/v1.0.rst
index 3e36438dda095..e3aa1af70f851 100644
--- a/doc/whats_new/v1.0.rst
+++ b/doc/whats_new/v1.0.rst
@@ -96,6 +96,10 @@ Changelog
   target. Additional private refactoring was performed.
   :pr:`19162` by :user:`Guillaume Lemaitre <glemaitre>`.
 
+- |Enhancement| Improve the HTML rendering of the
+  :class:`ensemble.StackingClassifier` and :class:`ensemble.StackingRegressor`.
+  :pr:`19564` by `Thomas Fan`_.
+
 :mod:`sklearn.feature_extraction`
 .................................