REF: dont consolidate in BlockManager.equals (pandas-dev#34962)

* REF: dont consolidate in BlockManager.equals

* doctest fixup

* Remove Block.equals

* simplify, comments

Author: jbrockmendel

pandas/core/internals/blocks.py

@@ -56,12 +56,7 @@
     ABCPandasArray,
     ABCSeries,
 )
-from pandas.core.dtypes.missing import (
-    _isna_compat,
-    array_equivalent,
-    is_valid_nat_for_dtype,
-    isna,
-)
+from pandas.core.dtypes.missing import _isna_compat, is_valid_nat_for_dtype, isna
 
 import pandas.core.algorithms as algos
 from pandas.core.array_algos.transforms import shift
@@ -1383,11 +1378,6 @@ def where_func(cond, values, other):
 
         return result_blocks
 
-    def equals(self, other) -> bool:
-        if self.dtype != other.dtype or self.shape != other.shape:
-            return False
-        return array_equivalent(self.values, other.values)
-
     def _unstack(self, unstacker, fill_value, new_placement):
         """
         Return a list of unstacked blocks of self
@@ -1881,9 +1871,6 @@ def where(
 
         return [self.make_block_same_class(result, placement=self.mgr_locs)]
 
-    def equals(self, other) -> bool:
-        return self.values.equals(other.values)
-
     def _unstack(self, unstacker, fill_value, new_placement):
         # ExtensionArray-safe unstack.
         # We override ObjectBlock._unstack, which unstacks directly on the
@@ -1929,12 +1916,6 @@ class NumericBlock(Block):
 class FloatOrComplexBlock(NumericBlock):
     __slots__ = ()
 
-    def equals(self, other) -> bool:
-        if self.dtype != other.dtype or self.shape != other.shape:
-            return False
-        left, right = self.values, other.values
-        return ((left == right) | (np.isnan(left) & np.isnan(right))).all()
-
 
 class FloatBlock(FloatOrComplexBlock):
     __slots__ = ()
@@ -2298,12 +2279,6 @@ def setitem(self, indexer, value):
         )
         return newb.setitem(indexer, value)
 
-    def equals(self, other) -> bool:
-        # override for significant performance improvement
-        if self.dtype != other.dtype or self.shape != other.shape:
-            return False
-        return (self.values.view("i8") == other.values.view("i8")).all()
-
     def quantile(self, qs, interpolation="linear", axis=0):
         naive = self.values.view("M8[ns]")
 

pandas/core/internals/managers.py

@@ -19,6 +19,7 @@
 from pandas.core.dtypes.common import (
     DT64NS_DTYPE,
     is_datetimelike_v_numeric,
+    is_dtype_equal,
     is_extension_array_dtype,
     is_list_like,
     is_numeric_v_string_like,
@@ -27,9 +28,10 @@
 from pandas.core.dtypes.concat import concat_compat
 from pandas.core.dtypes.dtypes import ExtensionDtype
 from pandas.core.dtypes.generic import ABCDataFrame, ABCSeries
-from pandas.core.dtypes.missing import isna
+from pandas.core.dtypes.missing import array_equivalent, isna
 
 import pandas.core.algorithms as algos
+from pandas.core.arrays import ExtensionArray
 from pandas.core.arrays.sparse import SparseDtype
 from pandas.core.base import PandasObject
 import pandas.core.common as com
@@ -1409,29 +1411,39 @@ def take(self, indexer, axis: int = 1, verify: bool = True, convert: bool = True
             new_axis=new_labels, indexer=indexer, axis=axis, allow_dups=True
         )
 
-    def equals(self, other) -> bool:
+    def equals(self, other: "BlockManager") -> bool:
         self_axes, other_axes = self.axes, other.axes
         if len(self_axes) != len(other_axes):
             return False
         if not all(ax1.equals(ax2) for ax1, ax2 in zip(self_axes, other_axes)):
             return False
-        self._consolidate_inplace()
-        other._consolidate_inplace()
-        if len(self.blocks) != len(other.blocks):
-            return False
 
-        # canonicalize block order, using a tuple combining the mgr_locs
-        # then type name because there might be unconsolidated
-        # blocks (say, Categorical) which can only be distinguished by
-        # the iteration order
-        def canonicalize(block):
-            return (block.mgr_locs.as_array.tolist(), block.dtype.name)
-
-        self_blocks = sorted(self.blocks, key=canonicalize)
-        other_blocks = sorted(other.blocks, key=canonicalize)
-        return all(
-            block.equals(oblock) for block, oblock in zip(self_blocks, other_blocks)
-        )
+        if self.ndim == 1:
+            # For SingleBlockManager (i.e.Series)
+            if other.ndim != 1:
+                return False
+            left = self.blocks[0].values
+            right = other.blocks[0].values
+            if not is_dtype_equal(left.dtype, right.dtype):
+                return False
+            elif isinstance(left, ExtensionArray):
+                return left.equals(right)
+            else:
+                return array_equivalent(left, right)
+
+        for i in range(len(self.items)):
+            # Check column-wise, return False if any column doesnt match
+            left = self.iget_values(i)
+            right = other.iget_values(i)
+            if not is_dtype_equal(left.dtype, right.dtype):
+                return False
+            elif isinstance(left, ExtensionArray):
+                if not left.equals(right):
+                    return False
+            else:
+                if not array_equivalent(left, right):
+                    return False
+        return True
 
     def unstack(self, unstacker, fill_value) -> "BlockManager":
         """

pandas/tests/internals/test_internals.py

@@ -377,7 +377,7 @@ def test_copy(self, mgr):
         for blk, cp_blk in zip(mgr.blocks, cp.blocks):
 
             # view assertion
-            assert cp_blk.equals(blk)
+            tm.assert_equal(cp_blk.values, blk.values)
             if isinstance(blk.values, np.ndarray):
                 assert cp_blk.values.base is blk.values.base
             else:
@@ -389,7 +389,7 @@ def test_copy(self, mgr):
 
             # copy assertion we either have a None for a base or in case of
             # some blocks it is an array (e.g. datetimetz), but was copied
-            assert cp_blk.equals(blk)
+            tm.assert_equal(cp_blk.values, blk.values)
             if not isinstance(cp_blk.values, np.ndarray):
                 assert cp_blk.values._data.base is not blk.values._data.base
             else: