shapely's cascaded_union was deprecated, replace with unary_union

src/c3nav/mapdata/migrations/0003_space_outside.py

@@ -3,13 +3,13 @@
 from __future__ import unicode_literals
 
 from django.db import migrations, models
-from shapely.ops import cascaded_union
+from shapely.ops import unary_union
 
 
 def set_space_outside(apps, schema_editor):
     Section = apps.get_model('mapdata', 'Section')
     for section in Section.objects.all():
-        building_geometries = cascaded_union(tuple(building.geometry for building in section.buildings.all()))
+        building_geometries = unary_union(tuple(building.geometry for building in section.buildings.all()))
         for space in section.spaces.all():
             if space.geometry.intersection(building_geometries).area / space.geometry.area < 0.5:
                 space.outside = True

src/c3nav/mapdata/models/level.py

@@ -7,7 +7,7 @@ from django.db import models
 from django.urls import reverse
 from django.utils.functional import cached_property
 from django.utils.translation import gettext_lazy as _
-from shapely.ops import cascaded_union
+from shapely.ops import unary_union
 
 from c3nav.mapdata.models.locations import SpecificLocation
 
@@ -94,8 +94,8 @@ class Level(SpecificLocation, models.Model):
 
     @cached_property
     def bounds(self):
-        return cascaded_union(tuple(item.geometry.buffer(0)
-                                    for item in chain(self.altitudeareas.all(), self.buildings.all()))).bounds
+        return unary_union(tuple(item.geometry.buffer(0)
+                                 for item in chain(self.altitudeareas.all(), self.buildings.all()))).bounds
 
     def get_icon(self):
         return super().get_icon() or 'layers'

src/c3nav/mapdata/utils/locations.py

@@ -10,7 +10,7 @@ from django.apps import apps
 from django.db.models import Prefetch, Q
 from django.utils.functional import cached_property
 from django.utils.translation import gettext_lazy as _
-from shapely.ops import cascaded_union
+from shapely.ops import unary_union
 
 from c3nav.mapdata.grid import grid
 from c3nav.mapdata.models import Level, Location, LocationGroup, MapUpdate
@@ -137,7 +137,7 @@ def get_better_space_geometries():
     result = {}
     for space in Space.objects.prefetch_related('columns', 'holes'):
         geometry = space.geometry.difference(
-            cascaded_union(tuple(obj.geometry for obj in chain(space.columns.all(), space.holes.all())))
+            unary_union(tuple(obj.geometry for obj in chain(space.columns.all(), space.holes.all())))
         )
         if not geometry.is_empty:
             result[space.pk] = geometry