Don't fail when plotting Series/DataFrame with no row

When Series or DataFrames was empty (no cells) after removing columns
without a suitable type (.select_dtypes), pandas was throwing a "no
numeric data to plot" exception.

This can happen:

1) either because there is no column with a suitable type;

2) or if there is no row.

Raising an exception in the first case makes sense but we should
probably avoid throwing an exception in the second case.

Author: Gabriel Corona

pandas/plotting/_matplotlib/core.py

@@ -418,7 +418,7 @@ def _compute_plot_data(self):
         numeric_data = data.select_dtypes(include=include_type, exclude=exclude_type)
 
         try:
-            is_empty = numeric_data.empty
+            is_empty = numeric_data.columns.empty
         except AttributeError:
             is_empty = not len(numeric_data)
 

pandas/tests/plotting/test_frame.py

@@ -3229,6 +3229,22 @@ def test_subplots_sharex_false(self):
         tm.assert_numpy_array_equal(axs[0].get_xticks(), expected_ax1)
         tm.assert_numpy_array_equal(axs[1].get_xticks(), expected_ax2)
 
+    def test_plot_no_rows(self):
+        df = pd.DataFrame({"foo": [1]},
+                         index=pd.Index(data=[], dtype=int),
+                         dtype="int")
+        assert df.empty
+        ax = df.plot()
+        assert len(ax.get_lines()) == 1
+        line = ax.get_lines()[0]
+        assert len(line.get_xdata()) == 0
+        assert len(line.get_ydata()) == 0
+
+    def test_plot_no_numeric_data(self):
+        df = pd.DataFrame(["a", "b", "c"])
+        with pytest.raises(TypeError):
+            df.plot()
+
 
 def _generate_4_axes_via_gridspec():
     import matplotlib.pyplot as plt