API/BUG: raise only KeyError failed on geitem/loc lookups

pandas/core/indexes/base.py

@@ -3111,7 +3111,7 @@ def _convert_scalar_indexer(self, key, kind: str_t):
 
             if kind == "getitem" and is_float(key):
                 if not self.is_floating():
-                    self._invalid_indexer("label", key)
+                    raise KeyError(key)
 
             elif kind == "loc" and is_float(key):
 
@@ -3125,11 +3125,11 @@ def _convert_scalar_indexer(self, key, kind: str_t):
                     "string",
                     "mixed",
                 ]:
-                    self._invalid_indexer("label", key)
+                    raise KeyError(key)
 
             elif kind == "loc" and is_integer(key):
                 if not self.holds_integer():
-                    self._invalid_indexer("label", key)
+                    raise KeyError(key)
 
         return key
 

pandas/core/indexes/category.py

@@ -598,7 +598,7 @@ def _convert_scalar_indexer(self, key, kind: str):
             try:
                 return self.categories._convert_scalar_indexer(key, kind="loc")
             except TypeError:
-                self._invalid_indexer("label", key)
+                raise KeyError(key)
         return super()._convert_scalar_indexer(key, kind=kind)
 
     @Appender(Index._convert_list_indexer.__doc__)

pandas/core/indexes/datetimelike.py

@@ -396,9 +396,9 @@ def _convert_scalar_indexer(self, key, kind: str):
         is_int = is_integer(key)
         is_flt = is_float(key)
         if kind == "loc" and (is_int or is_flt):
-            self._invalid_indexer("label", key)
+            raise KeyError(key)
         elif kind == "getitem" and is_flt:
-            self._invalid_indexer("label", key)
+            raise KeyError(key)
 
         return super()._convert_scalar_indexer(key, kind=kind)
 

pandas/core/indexing.py

@@ -1179,7 +1179,7 @@ def _convert_to_indexer(self, key, axis: int, is_setter: bool = False):
             # try to find out correct indexer, if not type correct raise
             try:
                 key = labels._convert_scalar_indexer(key, kind="loc")
-            except TypeError:
+            except KeyError:
                 # but we will allow setting
                 if not is_setter:
                     raise

pandas/tests/frame/test_constructors.py

@@ -1859,11 +1859,7 @@ def check(df):
 
             # No NaN found -> error
             if len(indexer) == 0:
-                msg = (
-                    "cannot do label indexing on RangeIndex "
-                    r"with these indexers \[nan\] of type float"
-                )
-                with pytest.raises(TypeError, match=msg):
+                with pytest.raises(KeyError, match="^nan$"):
                     df.loc[:, np.nan]
             # single nan should result in Series
             elif len(indexer) == 1:

pandas/tests/indexing/test_categorical.py

@@ -82,11 +82,7 @@ def test_loc_scalar(self):
         with pytest.raises(TypeError, match=msg):
             df.loc["d", "C"] = 10
 
-        msg = (
-            "cannot do label indexing on CategoricalIndex with these "
-            r"indexers \[1\] of type int"
-        )
-        with pytest.raises(TypeError, match=msg):
+        with pytest.raises(KeyError, match="^1$"):
             df.loc[1]
 
     def test_getitem_scalar(self):

pandas/tests/indexing/test_floats.py

@@ -93,11 +93,9 @@ def test_scalar_non_numeric(self, index_func, klass):
         # getting
         for idxr, getitem in [(lambda x: x.iloc, False), (lambda x: x, True)]:
 
-            # gettitem on a DataFrame is a KeyError as it is indexing
-            # via labels on the columns
-            if getitem and isinstance(s, DataFrame):
+            if getitem:
                 error = KeyError
-                msg = r"^3(\.0)?$"
+                msg = r"^3\.0?$"
             else:
                 error = TypeError
                 msg = (
@@ -116,6 +114,9 @@ def test_scalar_non_numeric(self, index_func, klass):
             "string",
             "unicode",
             "mixed",
+            "period",
+            "timedelta64",
+            "datetime64",
         }:
             error = KeyError
             msg = r"^3\.0$"
@@ -183,12 +184,7 @@ def test_scalar_non_numeric_series_fallback(self, index_func):
         i = index_func(5)
         s = Series(np.arange(len(i)), index=i)
         s[3]
-        msg = (
-            r"cannot do (label|positional) indexing "
-            fr"on {type(i).__name__} with these indexers \[3\.0\] of "
-            "type float"
-        )
-        with pytest.raises(TypeError, match=msg):
+        with pytest.raises(KeyError, match="^3.0$"):
             s[3.0]
 
     def test_scalar_with_mixed(self):
@@ -199,12 +195,12 @@ def test_scalar_with_mixed(self):
         # lookup in a pure stringstr
         # with an invalid indexer
         msg = (
-            "cannot do label indexing "
-            fr"on {Index.__name__} with these indexers \[1\.0\] of "
+            r"cannot do label indexing "
+            r"on Index with these indexers \[1\.0\] of "
             r"type float|"
             "Cannot index by location index with a non-integer key"
         )
-        with pytest.raises(TypeError, match=msg):
+        with pytest.raises(KeyError, match="^1.0$"):
             s2[1.0]
         with pytest.raises(TypeError, match=msg):
             s2.iloc[1.0]
@@ -218,12 +214,7 @@ def test_scalar_with_mixed(self):
 
         # mixed index so we have label
         # indexing
-        msg = (
-            "cannot do label indexing "
-            fr"on {Index.__name__} with these indexers \[1\.0\] of "
-            "type float"
-        )
-        with pytest.raises(TypeError, match=msg):
+        with pytest.raises(KeyError, match="^1.0$"):
             s3[1.0]
 
         result = s3[1]

pandas/tests/indexing/test_loc.py

@@ -16,7 +16,7 @@ class TestLoc(Base):
     def test_loc_getitem_int(self):
 
         # int label
-        self.check_result("loc", 2, typs=["labels"], fails=TypeError)
+        self.check_result("loc", 2, typs=["labels"], fails=KeyError)
 
     def test_loc_getitem_label(self):
 
@@ -34,8 +34,8 @@ def test_loc_getitem_label_out_of_range(self):
         self.check_result(
             "loc", 20, typs=["ints", "uints", "mixed"], fails=KeyError,
         )
-        self.check_result("loc", 20, typs=["labels"], fails=TypeError)
-        self.check_result("loc", 20, typs=["ts"], axes=0, fails=TypeError)
+        self.check_result("loc", 20, typs=["labels"], fails=KeyError)
+        self.check_result("loc", 20, typs=["ts"], axes=0, fails=KeyError)
         self.check_result("loc", 20, typs=["floats"], axes=0, fails=KeyError)
 
     def test_loc_getitem_label_list(self):

pandas/tests/indexing/test_scalar.py

@@ -137,13 +137,9 @@ def test_series_at_raises_type_error(self):
         result = ser.loc["a"]
         assert result == 1
 
-        msg = (
-            "cannot do label indexing on Index "
-            r"with these indexers \[0\] of type int"
-        )
-        with pytest.raises(TypeError, match=msg):
+        with pytest.raises(KeyError, match="^0$"):
             ser.at[0]
-        with pytest.raises(TypeError, match=msg):
+        with pytest.raises(KeyError, match="^0$"):
             ser.loc[0]
 
     def test_frame_raises_type_error(self):
@@ -154,13 +150,9 @@ def test_frame_raises_type_error(self):
         result = df.loc["a", "A"]
         assert result == 1
 
-        msg = (
-            "cannot do label indexing on Index "
-            r"with these indexers \[0\] of type int"
-        )
-        with pytest.raises(TypeError, match=msg):
+        with pytest.raises(KeyError, match="^0$"):
             df.at["a", 0]
-        with pytest.raises(TypeError, match=msg):
+        with pytest.raises(KeyError, match="^0$"):
             df.loc["a", 0]
 
     def test_series_at_raises_key_error(self):