PERF: avoid extraneous extract_array (#43147)

Author: jbrockmendel

asv_bench/benchmarks/frame_ctor.py

@@ -2,6 +2,7 @@
 
 import pandas as pd
 from pandas import (
+    Categorical,
     DataFrame,
     MultiIndex,
     Series,
@@ -31,6 +32,9 @@ def setup(self):
         self.dict_list = frame.to_dict(orient="records")
         self.data2 = {i: {j: float(j) for j in range(100)} for i in range(2000)}
 
+        # arrays which we wont consolidate
+        self.dict_of_categoricals = {i: Categorical(np.arange(N)) for i in range(K)}
+
     def time_list_of_dict(self):
         DataFrame(self.dict_list)
 
@@ -50,6 +54,10 @@ def time_nested_dict_int64(self):
         # nested dict, integer indexes, regression described in #621
         DataFrame(self.data2)
 
+    def time_dict_of_categoricals(self):
+        # dict of arrays that we wont consolidate
+        DataFrame(self.dict_of_categoricals)
+
 
 class FromSeries:
     def setup(self):

pandas/core/internals/construction.py

@@ -129,6 +129,7 @@ def arrays_to_mgr(
 
     else:
         index = ensure_index(index)
+        arrays = [extract_array(x, extract_numpy=True) for x in arrays]
 
         # Reached via DataFrame._from_arrays; we do validation here
         for arr in arrays:

pandas/core/internals/managers.py

@@ -1809,21 +1809,21 @@ def create_block_manager_from_blocks(
 
 
 def create_block_manager_from_column_arrays(
-    arrays,
+    arrays: list[ArrayLike],
     axes: list[Index],
     consolidate: bool = True,
 ) -> BlockManager:
     # Assertions disabled for performance (caller is responsible for verifying)
     # assert isinstance(axes, list)
     # assert all(isinstance(x, Index) for x in axes)
+    # assert all(isinstance(x, (np.ndarray, ExtensionArray)) for x in arrays)
+    # assert all(type(x) is not PandasArray for x in arrays)
     # assert all(x.ndim == 1 for x in arrays)
     # assert all(len(x) == len(axes[1]) for x in arrays)
     # assert len(arrays) == len(axes[0])
     # These last three are sufficient to allow us to safely pass
     #  verify_integrity=False below.
 
-    arrays = [extract_array(x, extract_numpy=True) for x in arrays]
-
     try:
         blocks = _form_blocks(arrays, consolidate)
         mgr = BlockManager(blocks, axes, verify_integrity=False)