MNT Reduce iteration over steps in _sk_visual_block_ (scikit-learn#29022)

Co-authored-by: Jérémie du Boisberranger <jeremie@probabl.ai>

Author: deepyaman

sklearn/pipeline.py

@@ -1312,15 +1312,15 @@ def __sklearn_is_fitted__(self):
             return False
 
     def _sk_visual_block_(self):
-        _, estimators = zip(*self.steps)
-
         def _get_name(name, est):
             if est is None or est == "passthrough":
                 return f"{name}: passthrough"
             # Is an estimator
             return f"{name}: {est.__class__.__name__}"
 
-        names = [_get_name(name, est) for name, est in self.steps]
+        names, estimators = zip(
+            *[(_get_name(name, est), est) for name, est in self.steps]
+        )
         name_details = [str(est) for est in estimators]
         return _VisualBlock(
             "serial",

sklearn/utils/_repr_html/tests/test_estimator.py

@@ -99,12 +99,12 @@ def test_get_visual_block_pipeline():
     est_html_info = _get_visual_block(pipe)
     assert est_html_info.kind == "serial"
     assert est_html_info.estimators == tuple(step[1] for step in pipe.steps)
-    assert est_html_info.names == [
+    assert est_html_info.names == (
         "imputer: SimpleImputer",
         "do_nothing: passthrough",
         "do_nothing_more: passthrough",
         "classifier: LogisticRegression",
-    ]
+    )
     assert est_html_info.name_details == [str(est) for _, est in pipe.steps]