ERR: Raise a better error for numpy singletons in Index (#33026)

Author: dsaxton

doc/source/whatsnew/v1.1.0.rst

@@ -336,6 +336,7 @@ Indexing
 - Bug in :meth:`DataFrame.iloc.__setitem__` on a :class:`DataFrame` with duplicate columns incorrectly setting values for all matching columns (:issue:`15686`, :issue:`22036`)
 - Bug in :meth:`DataFrame.loc:` and :meth:`Series.loc` with a :class:`DatetimeIndex`, :class:`TimedeltaIndex`, or :class:`PeriodIndex` incorrectly allowing lookups of non-matching datetime-like dtypes (:issue:`32650`)
 - Bug in :meth:`Series.__getitem__` indexing with non-standard scalars, e.g. ``np.dtype`` (:issue:`32684`)
+- Bug in :class:`Index` constructor where an unhelpful error message was raised for ``numpy`` scalars (:issue:`33017`)
 
 Missing
 ^^^^^^^

pandas/core/indexes/base.py

@@ -395,10 +395,10 @@ def __new__(
                 raise ValueError("Index data must be 1-dimensional")
             return cls._simple_new(subarr, name)
 
-        elif hasattr(data, "__array__"):
-            return Index(np.asarray(data), dtype=dtype, copy=copy, name=name, **kwargs)
         elif data is None or is_scalar(data):
             raise cls._scalar_data_error(data)
+        elif hasattr(data, "__array__"):
+            return Index(np.asarray(data), dtype=dtype, copy=copy, name=name, **kwargs)
         else:
             if tupleize_cols and is_list_like(data):
                 # GH21470: convert iterable to list before determining if empty

pandas/tests/indexes/base_class/test_constructors.py

@@ -1,3 +1,4 @@
+import numpy as np
 import pytest
 
 from pandas import Index, MultiIndex
@@ -7,14 +8,15 @@ class TestIndexConstructor:
     # Tests for the Index constructor, specifically for cases that do
     #  not return a subclass
 
-    def test_constructor_corner(self):
+    @pytest.mark.parametrize("value", [1, np.int64(1)])
+    def test_constructor_corner(self, value):
         # corner case
         msg = (
             r"Index\(\.\.\.\) must be called with a collection of some "
-            "kind, 0 was passed"
+            f"kind, {value} was passed"
         )
         with pytest.raises(TypeError, match=msg):
-            Index(0)
+            Index(value)
 
     @pytest.mark.parametrize("index_vals", [[("A", 1), "B"], ["B", ("A", 1)]])
     def test_construction_list_mixed_tuples(self, index_vals):