Reorder the logic of _update_title_position.

anntzer · anntzer · commit 5be80e72fd02 · 2019-03-25T10:38:05.000+01:00
- Replace try... except by explicit check for None (which is the only
  case triggering an exception).
- Move ymax computation out of the loop.
- Remove some unused variables (`y0`) and inline `choices`.
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -2514,10 +2514,8 @@ def _update_title_position(self, renderer):
                     return
             self._autotitlepos = True
 
-        ymax = -10
         for title in titles:
-            x, y0 = title.get_position()
-            y = 1
+            x, _ = title.get_position()
             # need to start again in case of window resizing
             title.set_position((x, 1.0))
             # need to check all our twins too...
@@ -2534,31 +2532,27 @@ def _update_title_position(self, renderer):
                     axs = axs + [ax]
             top = 0
             for ax in axs:
-                try:
-                    choices = ['top', 'unknown']
-                    if (ax.xaxis.get_label_position() == 'top' or
-                            ax.xaxis.get_ticks_position() in choices):
-                        bb = ax.xaxis.get_tightbbox(renderer)
-                    else:
-                        bb = ax.get_window_extent(renderer)
+                if (ax.xaxis.get_ticks_position() in ['top', 'unknown']
+                        or ax.xaxis.get_label_position() == 'top'):
+                    bb = ax.xaxis.get_tightbbox(renderer)
+                else:
+                    bb = ax.get_window_extent(renderer)
+                if bb is not None:
                     top = max(top, bb.ymax)
-                except AttributeError:
-                    # this happens for an empty bb
-                    y = 1
             if title.get_window_extent(renderer).ymin < top:
-                y = self.transAxes.inverted().transform(
-                        (0., top))[1]
+                _, y = self.transAxes.inverted().transform((0, top))
                 title.set_position((x, y))
                 # empirically, this doesn't always get the min to top,
                 # so we need to adjust again.
                 if title.get_window_extent(renderer).ymin < top:
                     _, y = self.transAxes.inverted().transform(
                         (0., 2 * top - title.get_window_extent(renderer).ymin))
                     title.set_position((x, y))
-            ymax = max(y, ymax)
+
+        ymax = max(title.get_position()[1] for title in titles)
         for title in titles:
             # now line up all the titles at the highest baseline.
-            x, y0 = title.get_position()
+            x, _ = title.get_position()
             title.set_position((x, ymax))
 
     # Drawing
