Closes Bears-R-Us#3213 Index properties

PROTO_tests/tests/index_test.py

@@ -1,5 +1,6 @@
 import pandas as pd
 import pytest
+from numpy import dtype as npdtype
 
 import arkouda as ak
 from arkouda.dtypes import dtype
@@ -52,6 +53,15 @@ def test_multiindex_creation(self, size):
         with pytest.raises(ValueError):
             idx = ak.MultiIndex([ak.arange(size), ak.arange(size - 1)])
 
+    def test_name_names(self):
+        i = ak.Index([1, 2, 3], name="test")
+        assert i.name == "test"
+        assert i.names == ["test"]
+
+        size = 10
+        m = ak.MultiIndex([ak.arange(size), ak.arange(size) * -1], names=["test", "test2"])
+        assert m.names == ["test", "test2"]
+
     def test_nlevels(self):
         i = ak.Index([1, 2, 3], name="test")
         assert i.nlevels == 1
@@ -60,6 +70,22 @@ def test_nlevels(self):
         m = ak.MultiIndex([ak.arange(size), ak.arange(size) * -1])
         assert m.nlevels == 2
 
+    def test_ndim(self):
+        i = ak.Index([1, 2, 3], name="test")
+        assert i.ndim == 1
+
+        size = 10
+        m = ak.MultiIndex([ak.arange(size), ak.arange(size) * -1])
+        assert m.ndim == 1
+
+    def test_dtypes(self):
+        size = 10
+        i = ak.Index(ak.arange(size, dtype="float64"))
+        assert i.dtype == dtype("float64")
+
+        m = ak.MultiIndex([ak.arange(size), ak.arange(size) * -1])
+        assert m.dtype == npdtype("O")
+
     def test_inferred_type(self):
         i = ak.Index([1, 2, 3])
         assert i.inferred_type == "integer"

arkouda/index.py

@@ -1,10 +1,11 @@
 from __future__ import annotations
 
 import json
-from typing import TYPE_CHECKING, List, Optional, Union, Tuple
+from typing import TYPE_CHECKING, List, Optional, Tuple, Union
 
 import pandas as pd  # type: ignore
 from numpy import array as ndarray
+from numpy import dtype as npdtype
 from typeguard import typechecked
 
 from arkouda import Categorical, Strings
@@ -194,6 +195,17 @@ def nlevels(self):
         """
         return 1
 
+    @property
+    def ndim(self):
+        """
+        Number of dimensions of the underlying data, by definition 1.
+
+        See Also
+        --------
+        MultiIndex.ndim
+        """
+        return 1
+
     @property
     def inferred_type(self) -> str:
         """
@@ -211,6 +223,13 @@ def inferred_type(self) -> str:
                 return "string"
         return self.values.inferred_type
 
+    @property
+    def names(self):
+        """
+        Return Index or MultiIndex names.
+        """
+        return [self.name]
+
     @property
     def index(self):
         """
@@ -986,7 +1005,7 @@ def __init__(
             raise TypeError("MultiIndex should be an iterable")
         self.levels = levels
         first = True
-        self.names = names
+        self._names = names
         self.name = name
         for col in self.levels:
             # col can be a python int which doesn't have a size attribute
@@ -1025,6 +1044,13 @@ def __eq__(self, v):
 
         return retval
 
+    @property
+    def names(self):
+        """
+        Return Index or MultiIndex names.
+        """
+        return self._names
+
     @property
     def index(self):
         return self.levels
@@ -1039,6 +1065,17 @@ def nlevels(self) -> int:
         """
         return len(self.levels)
 
+    @property
+    def ndim(self):
+        """
+        Number of dimensions of the underlying data, by definition 1.
+
+        See Also
+        --------
+        Index.ndim
+        """
+        return 1
+
     @property
     def inferred_type(self) -> str:
         return "mixed"
@@ -1065,6 +1102,13 @@ def get_level_values(self, level: Union[str, int]):
                 "an integer with absolute value less than the number of levels."
             )
 
+    @property
+    def dtype(self) -> npdtype:
+        """
+        Return the dtype object of the underlying data.
+        """
+        return npdtype("O")
+
     def memory_usage(self, unit="B"):
         """
         Return the memory usage of the MultiIndex levels.

tests/index_test.py

@@ -2,9 +2,11 @@
 import os
 import tempfile
 
+
 import pandas as pd
 from base_test import ArkoudaTest
 from context import arkouda as ak
+from numpy import dtype as npdtype
 
 from arkouda import io_util
 from arkouda.dtypes import dtype
@@ -61,6 +63,15 @@ def test_multiindex_creation(self):
         with self.assertRaises(ValueError):
             idx = ak.MultiIndex([ak.arange(5), ak.arange(3)])
 
+    def test_name_names(self):
+        i = ak.Index([1, 2, 3], name="test")
+        self.assertEqual(i.name, "test")
+        self.assertListEqual(i.names, ["test"])
+
+        size = 10
+        m = ak.MultiIndex([ak.arange(size), ak.arange(size) * -1], names=["test", "test2"])
+        self.assertListEqual(m.names, ["test", "test2"])
+
     def test_nlevels(self):
         i = ak.Index([1, 2, 3], name="test")
         assert i.nlevels == 1
@@ -69,6 +80,22 @@ def test_nlevels(self):
         m = ak.MultiIndex([ak.arange(size), ak.arange(size) * -1])
         assert m.nlevels == 2
 
+    def test_ndim(self):
+        i = ak.Index([1, 2, 3], name="test")
+        assert i.ndim == 1
+
+        size = 10
+        m = ak.MultiIndex([ak.arange(size), ak.arange(size) * -1])
+        assert m.ndim == 1
+
+    def test_dtypes(self):
+        size = 10
+        i = ak.Index(ak.arange(size, dtype="float64"))
+        assert i.dtype == dtype("float64")
+
+        m = ak.MultiIndex([ak.arange(size), ak.arange(size) * -1])
+        assert m.dtype == npdtype("O")
+
     def test_inferred_type(self):
         i = ak.Index([1, 2, 3])
         self.assertEqual(i.inferred_type, "integer")