[UK] New import command for post-2011 LSOAs/DZ/SOA

Author: ajparsons

mapit_gb/management/commands/mapit_UK_import_soa_2011.py

@@ -0,0 +1,123 @@
+# This script is used to import boundary polygons and other information
+# from shapefiles representing areas of census geography
+
+# Run as: ./manage.py mapit_UK_import_soa_2011 shapefile.shp --type=lsoa
+# --commit
+
+from django.core.management.base import LabelCommand
+from django.contrib.gis.gdal import DataSource
+from mapit.models import Area, Generation, Country, Type, NameType, CodeType
+from django.conf import settings
+from enum import Enum
+from mapit.management.command_utils import save_polygons
+
+
+class GeographyType(Enum):
+    """
+    allowed geographic imports
+    """
+    lsoa = "lsoa"
+    msoa = "msoa"
+    soa = "soa"
+    dz = "dz"
+    lz = "lz"
+
+    def __str__(self):
+        return self.value
+
+
+class Command(LabelCommand):
+    help = 'Creates Super Output Area boundaries from ONS/Scot Gov/OSNI shapefiles'
+    label = '<ONS SOA shapefile>'
+
+    def add_arguments(self, parser):
+        super(Command, self).add_arguments(parser)
+        parser.add_argument('--commit', action='store_true',
+                            dest='commit', help='Actually update the database')
+        parser.add_argument('--type', dest='file_type', help="options: lsoa, msoa, soa, dz, lz",
+                            type=GeographyType, choices=list(GeographyType)
+                            )
+        parser.add_argument('--generalized', action='store_true',
+                            dest='generalized', help='Is shape generalised?')
+
+    def handle_label(self, filename, **options):
+        self.stdout.write("Importing from %s" % filename)
+
+        current_generation = Generation.objects.current()
+        new_generation = Generation.objects.new()
+
+        file_type = options["file_type"].value.lower()
+        generalized = options["generalized"]
+
+        if file_type == "lsoa":  # England and Wales
+            feat_name = 'LSOA11NM'
+            feat_code = 'LSOA11CD'
+        elif file_type == "msoa":  # England and Wales
+            feat_name = 'MSOA11NM'
+            feat_code = 'MSOA11CD'
+        elif file_type == "soa":  # super output areas - NI
+            feat_name = 'SOA_LABEL'
+            feat_code = 'SOA_CODE'
+        elif file_type == "dz":  # datazone - scotland
+            feat_name = 'Name'
+            feat_code = 'DataZone'
+        elif file_type == "iz":  # intermediate zone - scotland
+            feat_name = 'Name'
+            feat_code = 'InterZone'
+        else:
+            raise Exception(
+                "Need to specify a small area type (lsoa, dz, soa, lz, msoa)")
+
+        if file_type in ["lsoa", "dz", "soa"]:
+            area_type = 'OLF'
+        elif file_type in ["msoa", "iz"]:
+            area_type = 'OMF'
+
+        if generalized:
+            area_type = area_type[:2] + "G"
+
+        ds = DataSource(filename)
+        layer = ds[0]
+        for feat in layer:
+            # retrieve name and code, and set country
+            name = feat[feat_name].value
+            code = feat[feat_code].value
+            if code[:2] == "95":
+                country = "N"
+            else:
+                country = code[0]
+
+            self.stdout.write("  looking at '%s' (%s)" % (name, code))
+
+            g = feat.geom.transform(settings.MAPIT_AREA_SRID, clone=True)
+
+            # skip if the SOA already exists in db (SOAs don't change)
+            areas = Area.objects.filter(type__code=area_type, codes__code=code)
+            if len(areas):
+                m = areas[0]
+                # check that we are not about to skip a generation
+                if m.generation_high and current_generation and m.generation_high.id < current_generation.id:
+                    raise Exception("Area %s found, but not in current generation %s" % (m, current_generation))
+                if m.generation_high != new_generation and options['commit']:
+                    m.generation_high = new_generation
+                    m.save()
+                continue
+
+            print("Adding %s (%s) %s" % (name, code, feat.geom.geom_name))
+            m = Area(
+                name=name,
+                type=Type.objects.get(code=area_type),
+                country=Country.objects.get(code=country),
+                generation_low=new_generation,
+                generation_high=new_generation,
+            )
+
+            poly = [g] if g is not None else []
+
+            if options['commit']:
+                m.save()
+                m.names.update_or_create(type=NameType.objects.get(
+                    code='S'), defaults={'name': name})
+                m.codes.update_or_create(type=CodeType.objects.get(
+                    code='ons'), defaults={'code': code})
+                save_polygons({m.id: (m, poly)})