Shorten contour._make_paths_from_contour_generator.

Author: anntzer

lib/matplotlib/contour.py

@@ -1114,22 +1114,14 @@ def _make_paths_from_contour_generator(self):
         """Compute ``paths`` using C extension."""
         if self._paths is not None:
             return self._paths
-        paths = []
+        cg = self._contour_generator
         empty_path = Path(np.empty((0, 2)))
-        if self.filled:
-            lowers, uppers = self._get_lowers_and_uppers()
-            for level, level_upper in zip(lowers, uppers):
-                vertices, kinds = \
-                    self._contour_generator.create_filled_contour(
-                        level, level_upper)
-                paths.append(Path(np.concatenate(vertices), np.concatenate(kinds))
-                             if len(vertices) else empty_path)
-        else:
-            for level in self.levels:
-                vertices, kinds = self._contour_generator.create_contour(level)
-                paths.append(Path(np.concatenate(vertices), np.concatenate(kinds))
-                             if len(vertices) else empty_path)
-        return paths
+        vertices_and_codes = (
+            map(cg.create_filled_contour, *self._get_lowers_and_uppers())
+            if self.filled else
+            map(cg.create_contour, self.levels))
+        return [Path(np.concatenate(vs), np.concatenate(cs)) if len(vs) else empty_path
+                for vs, cs in vertices_and_codes]
 
     def _get_lowers_and_uppers(self):
         """