some new features

.venv/lib/python3.12/site-packages/sklearn/utils/tests/test_missing.py

@@ -0,0 +1,27 @@
+import numpy as np
+import pytest
+
+from sklearn.utils._missing import is_scalar_nan
+
+
+@pytest.mark.parametrize(
+    "value, result",
+    [
+        (float("nan"), True),
+        (np.nan, True),
+        (float(np.nan), True),
+        (np.float32(np.nan), True),
+        (np.float64(np.nan), True),
+        (0, False),
+        (0.0, False),
+        (None, False),
+        ("", False),
+        ("nan", False),
+        ([np.nan], False),
+        (9867966753463435747313673, False),  # Python int that overflows with C type
+    ],
+)
+def test_is_scalar_nan(value, result):
+    assert is_scalar_nan(value) is result
+    # make sure that we are returning a Python bool
+    assert isinstance(is_scalar_nan(value), bool)