misplaced scatter/hexbin subplot colorbars (#21728)

Author: javadnoorb

doc/source/whatsnew/v0.24.0.txt

@@ -336,8 +336,7 @@ I/O
 Plotting
 ^^^^^^^^
 
-- Bug in :func:'DataFrame.plot.scatter' and :func:'DataFrame.plot.hexbin' caused x-axis label and ticklabels to disappear when colorbar was on in IPython inline backend (:issue:`10611` and :issue:`10678`)
--
+- Bug in :func:'DataFrame.plot.scatter' and :func:'DataFrame.plot.hexbin' caused x-axis label and ticklabels to disappear when colorbar was on in IPython inline backend (:issue:`10611`, :issue:`10678`, and :issue:`20455`)
 -
 
 Groupby/Resample/Rolling

pandas/plotting/_core.py

@@ -847,7 +847,7 @@ def _plot_colorbar(self, ax, **kwds):
         # https://github.com/ipython/ipython/issues/11215
 
         img = ax.collections[0]
-        cbar = self.fig.colorbar(img, **kwds)
+        cbar = self.fig.colorbar(img, ax=ax, **kwds)
         points = ax.get_position().get_points()
         cbar_points = cbar.ax.get_position().get_points()
         cbar.ax.set_position([cbar_points[0, 0],

pandas/tests/plotting/test_frame.py

@@ -1132,6 +1132,26 @@ def test_if_hexbin_xaxis_label_is_visible(self):
                     ax.xaxis.get_majorticklabels()])
         assert ax.xaxis.get_label().get_visible()
 
+    @pytest.mark.slow
+    def test_if_scatterplot_colorbars_are_next_to_parent_axes(self):
+        import matplotlib.pyplot as plt
+        random_array = np.random.random((1000, 3))
+        df = pd.DataFrame(random_array,
+                          columns=['A label', 'B label', 'C label'])
+
+        fig, axes = plt.subplots(1, 2)
+        df.plot.scatter('A label', 'B label', c='C label', ax=axes[0])
+        df.plot.scatter('A label', 'B label', c='C label', ax=axes[1])
+        plt.tight_layout()
+
+        points = np.array([ax.get_position().get_points()
+                           for ax in fig.axes])
+        axes_x_coords = points[:, :, 0]
+        parent_distance = axes_x_coords[1, :] - axes_x_coords[0, :]
+        colorbar_distance = axes_x_coords[3, :] - axes_x_coords[2, :]
+        assert np.isclose(parent_distance,
+                          colorbar_distance, atol=1e-7).all()
+
     @pytest.mark.slow
     def test_plot_scatter_with_categorical_data(self):
         # GH 16199