BUG: Fix #25481 by fixing the error message in TypeError

doc/source/whatsnew/v0.25.0.rst

@@ -121,7 +121,7 @@ Performance Improvements
 Bug Fixes
 ~~~~~~~~~
 - Bug in :func:`to_datetime` which would raise an (incorrect) ``ValueError`` when called with a date far into the future and the ``format`` argument specified instead of raising ``OutOfBoundsDatetime`` (:issue:`23830`)
--
+- Bug in an error message in :meth:`DataFrame.plot`. Improved the error message if non-numerics are passed to :meth:`DataFrame.plot` (:issue:`25481`)
 -
 
 Categorical

pandas/plotting/_core.py

@@ -358,10 +358,9 @@ def _compute_plot_data(self):
         except AttributeError:
             is_empty = not len(numeric_data)
 
-        # no empty frames or series allowed
+        # no non-numeric frames or series allowed
         if is_empty:
-            raise TypeError('Empty {0!r}: no numeric data to '
-                            'plot'.format(numeric_data.__class__.__name__))
+            raise TypeError('no numeric data to plot')
 
         self.data = numeric_data
 

pandas/tests/plotting/test_datetimelike.py

@@ -97,7 +97,7 @@ def test_nonnumeric_exclude(self):
         assert len(ax.get_lines()) == 1  # B was plotted
         self.plt.close(fig)
 
-        msg = "Empty 'DataFrame': no numeric data to plot"
+        msg = "no numeric data to plot"
         with pytest.raises(TypeError, match=msg):
             df['A'].plot()
 

pandas/tests/plotting/test_frame.py

@@ -485,7 +485,9 @@ def test_subplots_timeseries_y_axis(self):
         ax_datetime_all_tz = testdata.plot(y="datetime_all_tz")
         assert (ax_datetime_all_tz.get_lines()[0].get_data()[1] ==
                 testdata["datetime_all_tz"].values).all()
-        with pytest.raises(TypeError):
+
+        msg = "no numeric data to plot"
+        with pytest.raises(TypeError, match=msg):
             testdata.plot(y="text")
 
     @pytest.mark.xfail(reason='not support for period, categorical, '
@@ -2219,7 +2221,9 @@ def test_all_invalid_plot_data(self):
         for kind in plotting._core._common_kinds:
             if not _ok_for_gaussian_kde(kind):
                 continue
-            with pytest.raises(TypeError):
+
+            msg = "no numeric data to plot"
+            with pytest.raises(TypeError, match=msg):
                 df.plot(kind=kind)
 
     @pytest.mark.slow
@@ -2230,7 +2234,9 @@ def test_partially_invalid_plot_data(self):
             for kind in plotting._core._common_kinds:
                 if not _ok_for_gaussian_kde(kind):
                     continue
-                with pytest.raises(TypeError):
+
+                msg = "no numeric data to plot"
+                with pytest.raises(TypeError, match=msg):
                     df.plot(kind=kind)
 
         with tm.RNGContext(42):

pandas/tests/plotting/test_series.py

@@ -694,7 +694,9 @@ def test_invalid_plot_data(self):
         for kind in plotting._core._common_kinds:
             if not _ok_for_gaussian_kde(kind):
                 continue
-            with pytest.raises(TypeError):
+
+            msg = "no numeric data to plot"
+            with pytest.raises(TypeError, match=msg):
                 s.plot(kind=kind, ax=ax)
 
     @pytest.mark.slow
@@ -711,7 +713,9 @@ def test_partially_invalid_plot_data(self):
         for kind in plotting._core._common_kinds:
             if not _ok_for_gaussian_kde(kind):
                 continue
-            with pytest.raises(TypeError):
+
+            msg = "no numeric data to plot"
+            with pytest.raises(TypeError, match=msg):
                 s.plot(kind=kind, ax=ax)
 
     def test_invalid_kind(self):