FIX Show a HTML repr for meta-estimatosr with invalid parameters (#24015)

thomasjpfan · jeremiedbb · glemaitre · commit 7675a6ffb54a · 2022-08-05T14:58:55.000+02:00
Co-authored-by: Jérémie du Boisberranger &lt;34657725+jeremiedbb@users.noreply.github.com&gt;
diff --git a/doc/whats_new/v1.1.rst b/doc/whats_new/v1.1.rst
@@ -12,6 +12,9 @@ Version 1.1.2
 Changelog
 ---------
 
+- |Fix| A default HTML representation is shown for meta-estimators with invalid
+  parameters. :pr:`24015` by `Thomas Fan`_.
+
 :mod:`sklearn.cluster`
 ......................
 
diff --git a/sklearn/utils/_estimator_html_repr.py b/sklearn/utils/_estimator_html_repr.py
@@ -1,5 +1,4 @@
 from contextlib import closing
-from contextlib import suppress
 from io import StringIO
 from string import Template
 import html
@@ -103,8 +102,16 @@ def _write_label_html(
 
 def _get_visual_block(estimator):
     """Generate information about how to display an estimator."""
-    with suppress(AttributeError):
-        return estimator._sk_visual_block_()
+    if hasattr(estimator, "_sk_visual_block_"):
+        try:
+            return estimator._sk_visual_block_()
+        except Exception:
+            return _VisualBlock(
+                "single",
+                estimator,
+                names=estimator.__class__.__name__,
+                name_details=str(estimator),
+            )
 
     if isinstance(estimator, str):
         return _VisualBlock(
diff --git a/sklearn/utils/tests/test_estimator_html_repr.py b/sklearn/utils/tests/test_estimator_html_repr.py
@@ -309,3 +309,14 @@ def test_show_arrow_pipeline():
         'class="sk-toggleable__label sk-toggleable__label-arrow">Pipeline'
         in html_output
     )
+
+
+def test_invalid_parameters_in_stacking():
+    """Invalidate stacking configuration uses default repr.
+
+    Non-regression test for #24009.
+    """
+    stacker = StackingClassifier(estimators=[])
+
+    html_output = estimator_html_repr(stacker)
+    assert html.escape(str(stacker)) in html_output
