Optimize _remove_polygon_holes and _create_gdf for performance

CHANGELOG.md

@@ -40,6 +40,8 @@ Read the v2 [migration guide](https://github.com/gboeing/osmnx/issues/1123)
 - rename osm_xml module to \_osm_xml to make it private, as all its functions are private (#1113)
 - rename private \_downloader module to \_http (#1114)
 - remove unnecessary private \_api module (#1114)
+- optimize \_remove_polygon_holes function for improved performance with complex geometries (#1200)
+- enhance efficiency of \_create_gdf function in feature processing (#1200)
 
 ## 1.9.4 (2024-07-24)
 

osmnx/features.py

@@ -26,6 +26,7 @@
 from shapely import MultiPolygon
 from shapely import Point
 from shapely import Polygon
+from shapely import prepare
 from shapely.errors import GEOSException
 from shapely.ops import linemerge
 from shapely.ops import polygonize
@@ -409,8 +410,15 @@ def _create_gdf(
 
     # convert the elements into a GeoDataFrame of features
     idx = ["element", "id"]
-    features = _process_features(elements, set(tags.keys()))
-    gdf = gpd.GeoDataFrame(features, geometry="geometry", crs=settings.default_crs).set_index(idx)
+    gdf = (
+        gpd.GeoDataFrame(
+            data=_process_features(elements, set(tags.keys())),
+            geometry="geometry",
+            crs=settings.default_crs,
+        )
+        .set_index(idx)
+        .sort_index()
+    )
     return _filter_features(gdf, polygon, tags)
 
 
@@ -636,10 +644,9 @@ def _remove_polygon_holes(
         # otherwise, remove from each outer poly each inner poly it contains
         polygons_with_holes = []
         for outer in outer_polygons:
-            for inner in inner_polygons:
-                if outer.contains(inner):
-                    outer = outer.difference(inner)  # noqa: PLW2901
-            polygons_with_holes.append(outer)
+            prepare(outer)
+            holes = [inner for inner in inner_polygons if outer.contains(inner)]
+            polygons_with_holes.append(outer.difference(unary_union(holes)))
         geometry = unary_union(polygons_with_holes)
 
     # ensure returned geometry is a Polygon or MultiPolygon