14k -> 14.5k even faster path

pydata · May 5, 2024 · 29d7064 · 29d7064
1 parent 2e70989
commit 29d7064
Show file tree

Hide file tree

Showing 2 changed files with 24 additions and 11 deletions.
diff --git a/xarray/core/indexes.py b/xarray/core/indexes.py
@@ -575,13 +575,19 @@ class PandasIndex(Index):
 
     __slots__ = ("index", "dim", "coord_dtype")
 
-    def __init__(self, array: Any, dim: Hashable, coord_dtype: Any = None):
-        # make a shallow copy: cheap and because the index name may be updated
-        # here or in other constructors (cannot use pd.Index.rename as this
-        # constructor is also called from PandasMultiIndex)
-        index = safe_cast_to_index(array).copy()
+    def __init__(
+        self, array: Any, dim: Hashable, coord_dtype: Any = None, *, fastpath=False
+    ):
+        if fastpath:
+            index = array
+        else:
+            index = safe_cast_to_index(array)
 
         if index.name is None:
+            # make a shallow copy: cheap and because the index name may be updated
+            # here or in other constructors (cannot use pd.Index.rename as this
+            # constructor is also called from PandasMultiIndex)
+            index = index.copy()
             index.name = dim
 
         self.index = index
@@ -596,7 +602,7 @@ def _replace(self, index, dim=None, coord_dtype=None):
             dim = self.dim
         if coord_dtype is None:
             coord_dtype = self.coord_dtype
-        return type(self)(index, dim, coord_dtype)
+        return type(self)(index, dim, coord_dtype, fastpath=True)
 
     @classmethod
     def from_variables(
@@ -641,6 +647,8 @@ def from_variables(
 
         obj = cls(data, dim, coord_dtype=var.dtype)
         assert not isinstance(obj.index, pd.MultiIndex)
+        # Rename safely
+        obj.index = obj.index.copy()
         obj.index.name = name
 
         return obj
@@ -684,7 +692,7 @@ def concat(
         return cls(new_pd_index, dim=dim, coord_dtype=coord_dtype)
 
     def create_variables(
-        self, variables: Mapping[Any, Variable] | None = None
+        self, variables: Mapping[Any, Variable] | None = None, *, fastpath=False
     ) -> IndexVars:
         from xarray.core.variable import IndexVariable
 
@@ -701,7 +709,9 @@ def create_variables(
             encoding = None
 
         data = PandasIndexingAdapter(self.index, dtype=self.coord_dtype)
-        var = IndexVariable(self.dim, data, attrs=attrs, encoding=encoding)
+        var = IndexVariable(
+            self.dim, data, attrs=attrs, encoding=encoding, fastpath=fastpath
+        )
         return {name: var}
 
     def to_pandas_index(self) -> pd.Index:
@@ -1794,7 +1804,7 @@ def _apply_indexes_fast(indexes: Indexes[Index], args: Mapping[Any, Any], func:
             new_index = getattr(index, func)(index_args)
             if new_index is not None:
                 new_indexes.update({k: new_index for k in index_vars})
-                new_index_vars = new_index.create_variables(index_vars)
+                new_index_vars = new_index.create_variables(index_vars, fastpath=True)
                 new_index_variables.update(new_index_vars)
                 new_index_variables.update(new_index_vars)
             else:

diff --git a/xarray/core/indexing.py b/xarray/core/indexing.py
@@ -1662,10 +1662,13 @@ class PandasIndexingAdapter(ExplicitlyIndexedNDArrayMixin):
 
     __slots__ = ("array", "_dtype")
 
-    def __init__(self, array: pd.Index, dtype: DTypeLike = None):
+    def __init__(self, array: pd.Index, dtype: DTypeLike = None, *, fastpath=False):
         from xarray.core.indexes import safe_cast_to_index
 
-        self.array = safe_cast_to_index(array)
+        if fastpath:
+            self.array = array
+        else:
+            self.array = safe_cast_to_index(array)
 
         if dtype is None:
             self._dtype = get_valid_numpy_dtype(array)