done

lib/python3.11/site-packages/pandas/tests/arrays/test_ndarray_backed.py

@@ -0,0 +1,75 @@
+"""
+Tests for subclasses of NDArrayBackedExtensionArray
+"""
+import numpy as np
+
+from pandas import (
+    CategoricalIndex,
+    date_range,
+)
+from pandas.core.arrays import (
+    Categorical,
+    DatetimeArray,
+    NumpyExtensionArray,
+    TimedeltaArray,
+)
+
+
+class TestEmpty:
+    def test_empty_categorical(self):
+        ci = CategoricalIndex(["a", "b", "c"], ordered=True)
+        dtype = ci.dtype
+
+        # case with int8 codes
+        shape = (4,)
+        result = Categorical._empty(shape, dtype=dtype)
+        assert isinstance(result, Categorical)
+        assert result.shape == shape
+        assert result._ndarray.dtype == np.int8
+
+        # case where repr would segfault if we didn't override base implementation
+        result = Categorical._empty((4096,), dtype=dtype)
+        assert isinstance(result, Categorical)
+        assert result.shape == (4096,)
+        assert result._ndarray.dtype == np.int8
+        repr(result)
+
+        # case with int16 codes
+        ci = CategoricalIndex(list(range(512)) * 4, ordered=False)
+        dtype = ci.dtype
+        result = Categorical._empty(shape, dtype=dtype)
+        assert isinstance(result, Categorical)
+        assert result.shape == shape
+        assert result._ndarray.dtype == np.int16
+
+    def test_empty_dt64tz(self):
+        dti = date_range("2016-01-01", periods=2, tz="Asia/Tokyo")
+        dtype = dti.dtype
+
+        shape = (0,)
+        result = DatetimeArray._empty(shape, dtype=dtype)
+        assert result.dtype == dtype
+        assert isinstance(result, DatetimeArray)
+        assert result.shape == shape
+
+    def test_empty_dt64(self):
+        shape = (3, 9)
+        result = DatetimeArray._empty(shape, dtype="datetime64[ns]")
+        assert isinstance(result, DatetimeArray)
+        assert result.shape == shape
+
+    def test_empty_td64(self):
+        shape = (3, 9)
+        result = TimedeltaArray._empty(shape, dtype="m8[ns]")
+        assert isinstance(result, TimedeltaArray)
+        assert result.shape == shape
+
+    def test_empty_pandas_array(self):
+        arr = NumpyExtensionArray(np.array([1, 2]))
+        dtype = arr.dtype
+
+        shape = (3, 9)
+        result = NumpyExtensionArray._empty(shape, dtype=dtype)
+        assert isinstance(result, NumpyExtensionArray)
+        assert result.dtype == dtype
+        assert result.shape == shape