Remove redundant iteration through Axes._children.

QuLogic · QuLogic · commit 1022fe96ca22 · 2020-08-10T23:49:11.000-04:00
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -1886,10 +1886,13 @@ def _sci(self, im):
         `~.pyplot.viridis`, and other functions such as `~.pyplot.clim`.  The
         current image is an attribute of the current axes.
         """
+        cbook._check_isinstance(
+            (mpl.contour.ContourSet, mcoll.Collection, mimage.AxesImage),
+            im=im)
         if isinstance(im, mpl.contour.ContourSet):
-            if im.collections[0] not in self.collections:
+            if im.collections[0] not in self._children:
                 raise ValueError("ContourSet must be in current Axes")
-        elif im not in self.images and im not in self.collections:
+        elif im not in self._children:
             raise ValueError("Argument must be an image, collection, or "
                              "ContourSet in this Axes")
         self._current_image = im
@@ -1906,11 +1909,9 @@ def has_data(self):
         need to be updated, and may not actually be useful for
         anything.
         """
-        return (
-            len(self.collections) +
-            len(self.images) +
-            len(self.lines) +
-            len(self.patches)) > 0
+        return any(isinstance(a, (mcoll.Collection, mimage.AxesImage,
+                                  mlines.Line2D, mpatches.Patch))
+                   for a in self._children)
 
     def add_artist(self, a):
         """
@@ -2145,17 +2146,14 @@ def relim(self, visible_only=False):
         self.dataLim.set_points(mtransforms.Bbox.null().get_points())
         self.ignore_existing_data_limits = True
 
-        for line in self.lines:
-            if not visible_only or line.get_visible():
-                self._update_line_limits(line)
-
-        for p in self.patches:
-            if not visible_only or p.get_visible():
-                self._update_patch_limits(p)
-
-        for image in self.images:
-            if not visible_only or image.get_visible():
-                self._update_image_limits(image)
+        for artist in self._children:
+            if not visible_only or artist.get_visible():
+                if isinstance(artist, mlines.Line2D):
+                    self._update_line_limits(artist)
+                elif isinstance(artist, mpatches.Patch):
+                    self._update_patch_limits(artist)
+                elif isinstance(artist, mimage.AxesImage):
+                    self._update_image_limits(artist)
 
     def update_datalim(self, xys, updatex=True, updatey=True):
         """
diff --git a/lib/matplotlib/legend.py b/lib/matplotlib/legend.py
@@ -34,9 +34,9 @@
 from matplotlib.font_manager import FontProperties
 from matplotlib.lines import Line2D
 from matplotlib.patches import Patch, Rectangle, Shadow, FancyBboxPatch
-from matplotlib.collections import (LineCollection, RegularPolyCollection,
-                                    CircleCollection, PathCollection,
-                                    PolyCollection)
+from matplotlib.collections import (
+    Collection, CircleCollection, LineCollection, PathCollection,
+    PolyCollection, RegularPolyCollection)
 from matplotlib.transforms import Bbox, BboxBase, TransformedBbox
 from matplotlib.transforms import BboxTransformTo, BboxTransformFrom
 
@@ -831,18 +831,23 @@ def _auto_legend_data(self):
             List of (x, y) offsets of all collection.
         """
         assert self.isaxes  # always holds, as this is only called internally
-        ax = self.parent
-        lines = [line.get_transform().transform_path(line.get_path())
-                 for line in ax.lines]
-        bboxes = [patch.get_bbox().transformed(patch.get_data_transform())
-                  if isinstance(patch, Rectangle) else
-                  patch.get_path().get_extents(patch.get_transform())
-                  for patch in ax.patches]
+        bboxes = []
+        lines = []
         offsets = []
-        for handle in ax.collections:
-            _, transOffset, hoffsets, _ = handle._prepare_points()
-            for offset in transOffset.transform(hoffsets):
-                offsets.append(offset)
+        for artist in self.parent._children:
+            if isinstance(artist, Line2D):
+                lines.append(
+                    artist.get_transform().transform_path(artist.get_path()))
+            elif isinstance(artist, Rectangle):
+                bboxes.append(
+                    artist.get_bbox().transformed(artist.get_data_transform()))
+            elif isinstance(artist, Patch):
+                bboxes.append(
+                    artist.get_path().get_extents(artist.get_transform()))
+            elif isinstance(artist, Collection):
+                _, transOffset, hoffsets, _ = artist._prepare_points()
+                for offset in transOffset.transform(hoffsets):
+                    offsets.append(offset)
         return bboxes, lines, offsets
 
     def get_children(self):
@@ -1119,13 +1124,17 @@ def _get_legend_handles(axs, legend_handler_map=None):
     """
     handles_original = []
     for ax in axs:
-        handles_original += [*ax.lines, *ax.patches, *ax.collections,
-                             *ax.containers]
+        handles_original += [
+            *(a for a in ax._children
+              if isinstance(a, (Line2D, Patch, Collection))),
+            *ax.containers]
         # support parasite axes:
         if hasattr(ax, 'parasites'):
             for axx in ax.parasites:
-                handles_original += [*axx.lines, *axx.patches,
-                                     *axx.collections, *axx.containers]
+                handles_original += [
+                    *(a for a in axx._children
+                      if isinstance(a, (Line2D, Patch, Collection))),
+                    *axx.containers]
 
     handler_map = Legend.get_default_handler_map()
 
