PERF: Faster Series.__getattribute__

pandas/core/generic.py

@@ -4375,8 +4375,7 @@ def __getattr__(self, name):
                 name in self._accessors):
             return object.__getattribute__(self, name)
         else:
-            if (self._info_axis._can_hold_identifiers and
-                    name in self._info_axis):
+            if self._info_axis._can_hold_identifiers_and_holds_name(name):
                 return self[name]
             return object.__getattribute__(self, name)
 

pandas/core/indexes/base.py

@@ -2083,22 +2083,18 @@ def __getitem__(self, key):
         else:
             return result
 
-    @property
-    def _can_hold_identifiers(self):
+    def _can_hold_identifiers_and_holds_name(self, name):
         """
-        Whether the Index class *can* hold Python identifiers.
-
-        This is useful for short-circuting lookups in NDFrame.__getattr__.
-        Some index-classes can't hold identifiers (NumericIndex,
-        DatetimeIndex), so there's no reason to search the index when a user
-        does `Series.foo<TAB>`.
-
-        Note that we don't care about `foo` here. This just a property
-        of the index class itself, nothing to do with an instance.
+        Faster check for ``name in self`` when we know `name` is a Python
+        identifier (e.g. in NDFrame.__getattr__, which hits this to support
+        . key lookup). For indexes that can't hold identifiers (everything
+        but object & categorical) we just return False.
 
         https://github.com/pandas-dev/pandas/issues/19764
         """
-        return True
+        if self.is_object() or self.is_categorical():
+            return name in self
+        return False
 
     def append(self, other):
         """

pandas/core/indexes/interval.py

@@ -1303,12 +1303,6 @@ def __getitem__(self, value):
 
         return self._shallow_copy(left, right)
 
-    @property
-    def _can_hold_identifiers(self):
-        # perf: Intervals aren't valid Python identifiers.
-        # https://github.com/pandas-dev/pandas/issues/19764
-        return False
-
     # __repr__ associated methods are based on MultiIndex
 
     def _format_with_header(self, header, **kwargs):

pandas/core/indexes/numeric.py

@@ -114,12 +114,6 @@ def is_all_dates(self):
         """
         return False
 
-    @property
-    def _can_hold_identifiers(self):
-        # perf: Numeric elements are not valid identifiers.
-        # https://github.com/pandas-dev/pandas/issues/19764
-        return False
-
 
 _num_index_shared_docs['class_descr'] = """
     Immutable ndarray implementing an ordered, sliceable set. The basic object

pandas/tests/indexes/datetimelike.py

@@ -10,7 +10,8 @@ class DatetimeLike(Base):
 
     def test_can_hold_identifiers(self):
         idx = self.create_index()
-        assert idx._can_hold_identifiers is False
+        key = idx[0]
+        assert idx._can_hold_identifiers_and_holds_name(key) is False
 
     def test_shift_identity(self):
 

pandas/tests/indexes/test_base.py

@@ -68,7 +68,8 @@ def generate_index_types(self, skip_index_keys=[]):
 
     def test_can_hold_identifiers(self):
         idx = self.create_index()
-        assert idx._can_hold_identifiers is True
+        key = idx[0]
+        assert idx._can_hold_identifiers_and_holds_name(key) is True
 
     def test_new_axis(self):
         new_index = self.dateIndex[None, :]

pandas/tests/indexes/test_category.py

@@ -34,8 +34,9 @@ def create_index(self, categories=None, ordered=False):
             list('aabbca'), categories=categories, ordered=ordered)
 
     def test_can_hold_identifiers(self):
-        ci = self.create_index(categories=list('abcd'))
-        assert ci._can_hold_identifiers is True
+        idx = self.create_index(categories=list('abcd'))
+        key = idx[0]
+        assert idx._can_hold_identifiers_and_holds_name(key) is True
 
     def test_construction(self):
 

pandas/tests/indexes/test_multi.py

@@ -50,7 +50,8 @@ def create_index(self):
 
     def test_can_hold_identifiers(self):
         idx = self.create_index()
-        assert idx._can_hold_identifiers is True
+        key = idx[0]
+        assert idx._can_hold_identifiers_and_holds_name(key) is True
 
     def test_boolean_context_compat2(self):
 

pandas/tests/indexes/test_numeric.py

@@ -66,7 +66,8 @@ class Numeric(Base):
 
     def test_can_hold_identifiers(self):
         idx = self.create_index()
-        assert idx._can_hold_identifiers is False
+        key = idx[0]
+        assert idx._can_hold_identifiers_and_holds_name(key) is False
 
     def test_numeric_compat(self):
         pass  # override Base method

pandas/tests/indexes/test_range.py

@@ -46,7 +46,8 @@ def check_binop(self, ops, scalars, idxs):
 
     def test_can_hold_identifiers(self):
         idx = self.create_index()
-        assert idx._can_hold_identifiers is False
+        key = idx[0]
+        assert idx._can_hold_identifiers_and_holds_name(key) is False
 
     def test_binops(self):
         ops = [operator.add, operator.sub, operator.mul, operator.floordiv,