CLN: No need to use libindex.get_value_at (#31506)

Author: jbrockmendel

pandas/core/base.py

@@ -1027,12 +1027,10 @@ def tolist(self):
         --------
         numpy.ndarray.tolist
         """
-        if self.dtype.kind in ["m", "M"]:
-            return [com.maybe_box_datetimelike(x) for x in self._values]
-        elif is_extension_array_dtype(self._values):
+        if not isinstance(self._values, np.ndarray):
+            # check for ndarray instead of dtype to catch DTA/TDA
             return list(self._values)
-        else:
-            return self._values.tolist()
+        return self._values.tolist()
 
     to_list = tolist
 
@@ -1049,9 +1047,8 @@ def __iter__(self):
         iterator
         """
         # We are explicitly making element iterators.
-        if self.dtype.kind in ["m", "M"]:
-            return map(com.maybe_box_datetimelike, self._values)
-        elif is_extension_array_dtype(self._values):
+        if not isinstance(self._values, np.ndarray):
+            # Check type instead of dtype to catch DTA/TDA
             return iter(self._values)
         else:
             return map(self._values.item, range(self._values.size))

pandas/core/frame.py

@@ -2900,12 +2900,8 @@ def _get_value(self, index, col, takeable: bool = False):
         engine = self.index._engine
 
         try:
-            if isinstance(series._values, np.ndarray):
-                # i.e. not EA, we can use engine
-                return engine.get_value(series._values, index)
-            else:
-                loc = series.index.get_loc(index)
-                return series._values[loc]
+            loc = engine.get_loc(index)
+            return series._values[loc]
         except KeyError:
             # GH 20629
             if self.index.nlevels > 1:

pandas/core/indexes/base.py

@@ -4624,10 +4624,6 @@ def _get_values_for_loc(self, series, loc):
         Assumes that `series.index is self`
         """
         if is_integer(loc):
-            if isinstance(series._values, np.ndarray):
-                # Since we have an ndarray and not DatetimeArray, we dont
-                #  have to worry about a tz.
-                return libindex.get_value_at(series._values, loc, tz=None)
             return series._values[loc]
 
         return series.iloc[loc]

pandas/core/series.py

@@ -22,7 +22,7 @@
 
 from pandas._config import get_option
 
-from pandas._libs import index as libindex, lib, properties, reshape, tslibs
+from pandas._libs import lib, properties, reshape, tslibs
 from pandas._typing import Label
 from pandas.compat.numpy import function as nv
 from pandas.util._decorators import Appender, Substitution
@@ -838,13 +838,7 @@ def _ixs(self, i: int, axis: int = 0):
         -------
         scalar (int) or Series (slice, sequence)
         """
-
-        # dispatch to the values if we need
-        values = self._values
-        if isinstance(values, np.ndarray):
-            return libindex.get_value_at(values, i)
-        else:
-            return values[i]
+        return self._values[i]
 
     def _slice(self, slobj: slice, axis: int = 0, kind=None) -> "Series":
         slobj = self.index._convert_slice_indexer(slobj, kind=kind or "getitem")
@@ -981,7 +975,7 @@ def _get_value(self, label, takeable: bool = False):
         scalar value
         """
         if takeable:
-            return com.maybe_box_datetimelike(self._values[label])
+            return self._values[label]
         return self.index.get_value(self, label)
 
     def __setitem__(self, key, value):

pandas/tests/indexes/period/test_indexing.py

@@ -486,15 +486,17 @@ def test_get_value_datetime_hourly(self, freq):
             assert ser.loc[ts2] == 7
 
     def test_get_value_integer(self):
+        msg = "index 16801 is out of bounds for axis 0 with size 3"
         dti = pd.date_range("2016-01-01", periods=3)
         pi = dti.to_period("D")
         ser = pd.Series(range(3), index=pi)
-        with pytest.raises(IndexError, match="index out of bounds"):
+        with pytest.raises(IndexError, match=msg):
             pi.get_value(ser, 16801)
 
+        msg = "index 46 is out of bounds for axis 0 with size 3"
         pi2 = dti.to_period("Y")  # duplicates, ordinals are all 46
         ser2 = pd.Series(range(3), index=pi2)
-        with pytest.raises(IndexError, match="index out of bounds"):
+        with pytest.raises(IndexError, match=msg):
             pi2.get_value(ser2, 46)
 
     def test_is_monotonic_increasing(self):

pandas/tests/series/indexing/test_indexing.py

@@ -17,10 +17,9 @@
 def test_basic_indexing():
     s = Series(np.random.randn(5), index=["a", "b", "a", "a", "b"])
 
-    msg = "index out of bounds"
+    msg = "index 5 is out of bounds for axis 0 with size 5"
     with pytest.raises(IndexError, match=msg):
         s[5]
-    msg = "index 5 is out of bounds for axis 0 with size 5"
     with pytest.raises(IndexError, match=msg):
         s[5] = 0
 
@@ -29,7 +28,6 @@ def test_basic_indexing():
 
     s = s.sort_index()
 
-    msg = r"index out of bounds|^5$"
     with pytest.raises(IndexError, match=msg):
         s[5]
     msg = r"index 5 is out of bounds for axis (0|1) with size 5|^5$"
@@ -165,11 +163,12 @@ def test_getitem_with_duplicates_indices(result_1, duplicate_item, expected_1):
 
 def test_getitem_out_of_bounds(datetime_series):
     # don't segfault, GH #495
-    msg = "index out of bounds"
+    msg = r"index \d+ is out of bounds for axis 0 with size \d+"
     with pytest.raises(IndexError, match=msg):
         datetime_series[len(datetime_series)]
 
     # GH #917
+    msg = r"index -\d+ is out of bounds for axis 0 with size \d+"
     s = Series([], dtype=object)
     with pytest.raises(IndexError, match=msg):
         s[-1]

pandas/tests/series/indexing/test_numeric.py

@@ -71,10 +71,9 @@ def test_slice_float64():
 def test_getitem_negative_out_of_bounds():
     s = Series(tm.rands_array(5, 10), index=tm.rands_array(10, 10))
 
-    msg = "index out of bounds"
+    msg = "index -11 is out of bounds for axis 0 with size 10"
     with pytest.raises(IndexError, match=msg):
         s[-11]
-    msg = "index -11 is out of bounds for axis 0 with size 10"
     with pytest.raises(IndexError, match=msg):
         s[-11] = "foo"