TST: add message matches to pytest.raises in various tests GH30999 (#…

…38350)

pandas/tests/io/pytables/test_complex.py

@@ -149,17 +149,34 @@ def test_complex_indexing_error(setup_path):
         {"A": [1, 2, 3, 4], "B": ["a", "b", "c", "d"], "C": complex128},
         index=list("abcd"),
     )
+
+    msg = (
+        "Columns containing complex values can be stored "
+        "but cannot be indexed when using table format. "
+        "Either use fixed format, set index=False, "
+        "or do not include the columns containing complex "
+        "values to data_columns when initializing the table."
+    )
+
     with ensure_clean_store(setup_path) as store:
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             store.append("df", df, data_columns=["C"])
 
 
 def test_complex_series_error(setup_path):
     complex128 = np.array([1.0 + 1.0j, 1.0 + 1.0j, 1.0 + 1.0j, 1.0 + 1.0j])
     s = Series(complex128, index=list("abcd"))
 
+    msg = (
+        "Columns containing complex values can be stored "
+        "but cannot be indexed when using table format. "
+        "Either use fixed format, set index=False, "
+        "or do not include the columns containing complex "
+        "values to data_columns when initializing the table."
+    )
+
     with ensure_clean_path(setup_path) as path:
-        with pytest.raises(TypeError):
+        with pytest.raises(TypeError, match=msg):
             s.to_hdf(path, "obj", format="t")
 
     with ensure_clean_path(setup_path) as path:

pandas/tests/io/test_clipboard.py

@@ -238,10 +238,11 @@ def test_read_clipboard_infer_excel(self, request, mock_clipboard):
         tm.assert_frame_equal(res, exp)
 
     def test_invalid_encoding(self, df):
+        msg = "clipboard only supports utf-8 encoding"
         # test case for testing invalid encoding
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match=msg):
             df.to_clipboard(encoding="ascii")
-        with pytest.raises(NotImplementedError):
+        with pytest.raises(NotImplementedError, match=msg):
             pd.read_clipboard(encoding="ascii")
 
     @pytest.mark.parametrize("enc", ["UTF-8", "utf-8", "utf8"])

pandas/tests/plotting/frame/test_frame_subplots.py

@@ -218,9 +218,13 @@ def test_subplots_layout_multi_column(self):
         self._check_axes_shape(axes, axes_num=3, layout=(4, 1))
         assert axes.shape == (4, 1)
 
-        with pytest.raises(ValueError):
+        msg = "Layout of 1x1 must be larger than required size 3"
+
+        with pytest.raises(ValueError, match=msg):
             df.plot(subplots=True, layout=(1, 1))
-        with pytest.raises(ValueError):
+
+        msg = "At least one dimension of layout must be positive"
+        with pytest.raises(ValueError, match=msg):
             df.plot(subplots=True, layout=(-1, -1))
 
     @pytest.mark.parametrize(
@@ -272,7 +276,9 @@ def test_subplots_multiple_axes(self):
         self._check_axes_shape(axes, axes_num=6, layout=(2, 3))
         tm.close()
 
-        with pytest.raises(ValueError):
+        msg = "The number of passed axes must be 3, the same as the output plot"
+
+        with pytest.raises(ValueError, match=msg):
             fig, axes = self.plt.subplots(2, 3)
             # pass different number of axes from required
             df.plot(subplots=True, ax=axes)