done

lib/python3.11/site-packages/pandas/tests/base/test_transpose.py

@@ -0,0 +1,56 @@
+import numpy as np
+import pytest
+
+from pandas import (
+    CategoricalDtype,
+    DataFrame,
+)
+import pandas._testing as tm
+
+
+def test_transpose(index_or_series_obj):
+    obj = index_or_series_obj
+    tm.assert_equal(obj.transpose(), obj)
+
+
+def test_transpose_non_default_axes(index_or_series_obj):
+    msg = "the 'axes' parameter is not supported"
+    obj = index_or_series_obj
+    with pytest.raises(ValueError, match=msg):
+        obj.transpose(1)
+    with pytest.raises(ValueError, match=msg):
+        obj.transpose(axes=1)
+
+
+def test_numpy_transpose(index_or_series_obj):
+    msg = "the 'axes' parameter is not supported"
+    obj = index_or_series_obj
+    tm.assert_equal(np.transpose(obj), obj)
+
+    with pytest.raises(ValueError, match=msg):
+        np.transpose(obj, axes=1)
+
+
+@pytest.mark.parametrize(
+    "data, transposed_data, index, columns, dtype",
+    [
+        ([[1], [2]], [[1, 2]], ["a", "a"], ["b"], int),
+        ([[1], [2]], [[1, 2]], ["a", "a"], ["b"], CategoricalDtype([1, 2])),
+        ([[1, 2]], [[1], [2]], ["b"], ["a", "a"], int),
+        ([[1, 2]], [[1], [2]], ["b"], ["a", "a"], CategoricalDtype([1, 2])),
+        ([[1, 2], [3, 4]], [[1, 3], [2, 4]], ["a", "a"], ["b", "b"], int),
+        (
+            [[1, 2], [3, 4]],
+            [[1, 3], [2, 4]],
+            ["a", "a"],
+            ["b", "b"],
+            CategoricalDtype([1, 2, 3, 4]),
+        ),
+    ],
+)
+def test_duplicate_labels(data, transposed_data, index, columns, dtype):
+    # GH 42380
+    df = DataFrame(data, index=index, columns=columns, dtype=dtype)
+    result = df.T
+    expected = DataFrame(transposed_data, index=columns, columns=index, dtype=dtype)
+    tm.assert_frame_equal(result, expected)