DEPR: make_block (pandas-dev#56422)

* DEPR: make_block

* lint fixup

Author: jbrockmendel

doc/source/whatsnew/v2.2.0.rst

@@ -432,6 +432,7 @@ Other Deprecations
 ^^^^^^^^^^^^^^^^^^
 - Changed :meth:`Timedelta.resolution_string` to return ``h``, ``min``, ``s``, ``ms``, ``us``, and ``ns`` instead of ``H``, ``T``, ``S``, ``L``, ``U``, and ``N``, for compatibility with respective deprecations in frequency aliases (:issue:`52536`)
 - Deprecated :func:`pandas.api.types.is_interval` and :func:`pandas.api.types.is_period`, use ``isinstance(obj, pd.Interval)`` and ``isinstance(obj, pd.Period)`` instead (:issue:`55264`)
+- Deprecated :func:`pd.core.internals.api.make_block`, use public APIs instead (:issue:`40226`)
 - Deprecated :func:`read_gbq` and :meth:`DataFrame.to_gbq`. Use ``pandas_gbq.read_gbq`` and ``pandas_gbq.to_gbq`` instead https://pandas-gbq.readthedocs.io/en/latest/api.html (:issue:`55525`)
 - Deprecated :meth:`.DataFrameGroupBy.fillna` and :meth:`.SeriesGroupBy.fillna`; use :meth:`.DataFrameGroupBy.ffill`, :meth:`.DataFrameGroupBy.bfill` for forward and backward filling or :meth:`.DataFrame.fillna` to fill with a single value (or the Series equivalents) (:issue:`55718`)
 - Deprecated :meth:`Index.format`, use ``index.astype(str)`` or ``index.map(formatter)`` instead (:issue:`55413`)
@@ -484,7 +485,6 @@ Other Deprecations
 - Deprecated the extension test classes ``BaseNoReduceTests``, ``BaseBooleanReduceTests``, and ``BaseNumericReduceTests``, use ``BaseReduceTests`` instead (:issue:`54663`)
 - Deprecated the option ``mode.data_manager`` and the ``ArrayManager``; only the ``BlockManager`` will be available in future versions (:issue:`55043`)
 - Deprecated the previous implementation of :class:`DataFrame.stack`; specify ``future_stack=True`` to adopt the future version (:issue:`53515`)
--
 
 .. ---------------------------------------------------------------------------
 .. _whatsnew_220.performance:

pandas/core/internals/api.py

@@ -9,10 +9,12 @@
 from __future__ import annotations
 
 from typing import TYPE_CHECKING
+import warnings
 
 import numpy as np
 
 from pandas._libs.internals import BlockPlacement
+from pandas.util._exceptions import find_stack_level
 
 from pandas.core.dtypes.common import pandas_dtype
 from pandas.core.dtypes.dtypes import (
@@ -50,6 +52,14 @@ def make_block(
     - Block.make_block_same_class
     - Block.__init__
     """
+    warnings.warn(
+        # GH#40226
+        "make_block is deprecated and will be removed in a future version. "
+        "Use public APIs instead.",
+        DeprecationWarning,
+        stacklevel=find_stack_level(),
+    )
+
     if dtype is not None:
         dtype = pandas_dtype(dtype)
 
@@ -113,7 +123,6 @@ def maybe_infer_ndim(values, placement: BlockPlacement, ndim: int | None) -> int
 
 def __getattr__(name: str):
     # GH#55139
-    import warnings
 
     if name in [
         "Block",

pandas/tests/internals/test_api.py

@@ -68,7 +68,9 @@ def test_deprecations(name):
 def test_make_block_2d_with_dti():
     # GH#41168
     dti = pd.date_range("2012", periods=3, tz="UTC")
-    blk = api.make_block(dti, placement=[0])
+    msg = "make_block is deprecated"
+    with tm.assert_produces_warning(DeprecationWarning, match=msg):
+        blk = api.make_block(dti, placement=[0])
 
     assert blk.shape == (1, 3)
     assert blk.values.shape == (1, 3)

pandas/tests/internals/test_internals.py

@@ -1383,9 +1383,11 @@ def test_validate_ndim():
     values = np.array([1.0, 2.0])
     placement = BlockPlacement(slice(2))
     msg = r"Wrong number of dimensions. values.ndim != ndim \[1 != 2\]"
+    depr_msg = "make_block is deprecated"
 
     with pytest.raises(ValueError, match=msg):
-        make_block(values, placement, ndim=2)
+        with tm.assert_produces_warning(DeprecationWarning, match=depr_msg):
+            make_block(values, placement, ndim=2)
 
 
 def test_block_shape():
@@ -1400,23 +1402,29 @@ def test_make_block_no_pandas_array(block_maker):
     # https://github.com/pandas-dev/pandas/pull/24866
     arr = pd.arrays.NumpyExtensionArray(np.array([1, 2]))
 
+    warn = None if block_maker is not make_block else DeprecationWarning
+    msg = "make_block is deprecated and will be removed in a future version"
+
     # NumpyExtensionArray, no dtype
-    result = block_maker(arr, BlockPlacement(slice(len(arr))), ndim=arr.ndim)
+    with tm.assert_produces_warning(warn, match=msg):
+        result = block_maker(arr, BlockPlacement(slice(len(arr))), ndim=arr.ndim)
     assert result.dtype.kind in ["i", "u"]
 
     if block_maker is make_block:
         # new_block requires caller to unwrap NumpyExtensionArray
         assert result.is_extension is False
 
         # NumpyExtensionArray, NumpyEADtype
-        result = block_maker(arr, slice(len(arr)), dtype=arr.dtype, ndim=arr.ndim)
+        with tm.assert_produces_warning(warn, match=msg):
+            result = block_maker(arr, slice(len(arr)), dtype=arr.dtype, ndim=arr.ndim)
         assert result.dtype.kind in ["i", "u"]
         assert result.is_extension is False
 
         # new_block no longer taked dtype keyword
         # ndarray, NumpyEADtype
-        result = block_maker(
-            arr.to_numpy(), slice(len(arr)), dtype=arr.dtype, ndim=arr.ndim
-        )
+        with tm.assert_produces_warning(warn, match=msg):
+            result = block_maker(
+                arr.to_numpy(), slice(len(arr)), dtype=arr.dtype, ndim=arr.ndim
+            )
         assert result.dtype.kind in ["i", "u"]
         assert result.is_extension is False

pandas/tests/io/parser/common/test_chunksize.py

@@ -233,6 +233,7 @@ def test_chunks_have_consistent_numerical_type(all_parsers, monkeypatch):
     assert result.a.dtype == float
 
 
+@pytest.mark.filterwarnings("ignore:make_block is deprecated:FutureWarning")
 def test_warn_if_chunks_have_mismatched_type(all_parsers):
     warning_type = None
     parser = all_parsers

pandas/tests/io/parser/test_parse_dates.py

@@ -33,9 +33,12 @@
 
 from pandas.io.parsers import read_csv
 
-pytestmark = pytest.mark.filterwarnings(
-    "ignore:Passing a BlockManager to DataFrame:DeprecationWarning"
-)
+pytestmark = [
+    pytest.mark.filterwarnings(
+        "ignore:Passing a BlockManager to DataFrame:DeprecationWarning"
+    ),
+    pytest.mark.filterwarnings("ignore:make_block is deprecated:DeprecationWarning"),
+]
 
 xfail_pyarrow = pytest.mark.usefixtures("pyarrow_xfail")
 skip_pyarrow = pytest.mark.usefixtures("pyarrow_skip")