Cleanup imshow_extent tutorial.

anntzer · anntzer · commit c2c64f8165da · 2020-04-02T00:46:16.000+02:00
- Move title-setting out to make it hopefully clearer (it's the first
  row that matters, not the one with `extent=None`).
- Define the kwargs to annotate() at a single call site rather than in a
  separate dict.
- Add show() to make the example runnable from the command-line.
diff --git a/tutorials/intermediate/imshow_extent.py b/tutorials/intermediate/imshow_extent.py
@@ -148,21 +148,15 @@ def generate_imshow_demo_grid(extents, xlim=None, ylim=None):
         for ax, extent in zip(columns[origin], extents):
             plot_imshow_with_labels(ax, data, extent, origin, xlim, ylim)
 
+    columns['label'][0].set_title('extent=')
     for ax, extent in zip(columns['label'], extents):
-        text_kwargs = {'ha': 'right',
-                       'va': 'center',
-                       'xycoords': 'axes fraction',
-                       'xy': (1, .5)}
         if extent is None:
-            ax.annotate('None', **text_kwargs)
-            ax.set_title('extent=')
+            text = 'None'
         else:
             left, right, bottom, top = extent
-            text = ('left: {left:0.1f}\nright: {right:0.1f}\n' +
-                    'bottom: {bottom:0.1f}\ntop: {top:0.1f}\n').format(
-                        left=left, right=right, bottom=bottom, top=top)
-
-            ax.annotate(text, **text_kwargs)
+            text = (f'left: {left:0.1f}\nright: {right:0.1f}\n'
+                    f'bottom: {bottom:0.1f}\ntop: {top:0.1f}\n')
+        ax.text(1., .5, text, transform=ax.transAxes, ha='right', va='center')
         ax.axis('off')
     return columns
 
@@ -263,3 +257,6 @@ def generate_imshow_demo_grid(extents, xlim=None, ylim=None):
 
 generate_imshow_demo_grid(extents=[None] + extents,
                           xlim=(-2, 8), ylim=(-1, 6))
+
+
+plt.show()
