Files
notifications-admin/app/broadcast_areas/create-broadcast-areas-db.py
Leo Hemsted f806ffc2f6 add keep-old-features flag
got annoyed waiting to regenerate unsimplified geometry
2020-09-09 14:29:02 +01:00

246 lines
7.7 KiB
Python
Executable File

#!/usr/bin/env python
import csv
import sys
from pathlib import Path
import geojson
from notifications_utils.formatters import formatted_list
from polygons import Polygons
from repo import BroadcastAreasRepository
source_files_path = Path(__file__).resolve().parent / 'source_files'
point_counts = []
def simplify_geometry(feature):
if feature["type"] == "Polygon":
return [feature["coordinates"][0]]
elif feature["type"] == "MultiPolygon":
return [polygon for polygon, *_holes in feature["coordinates"]]
else:
raise Exception("Unknown type: {}".format(feature["type"]))
def polygons_and_simplified_polygons(feature):
if keep_old_polygons:
# cheat and shortcut out
return [], []
polygons = Polygons(simplify_geometry(feature))
full_resolution = polygons.remove_too_small
smoothed = full_resolution.smooth
simplified = smoothed.simplify
print( # noqa: T001
f' Original:{full_resolution.point_count: >5} points'
f' Smoothed:{smoothed.point_count: >5} points'
f' Simplified:{simplified.point_count: >4} points'
)
point_counts.append(simplified.point_count)
if simplified.point_count >= 200:
raise RuntimeError(
'Too many points '
'(adjust Polygons.perimeter_to_simplification_ratio or '
'Polygons.perimeter_to_buffer_ratio)'
)
return (
full_resolution.as_coordinate_pairs_long_lat,
simplified.as_coordinate_pairs_long_lat,
)
ctry19_filepath = source_files_path / "Countries.geojson"
# https://geoportal.statistics.gov.uk/datasets/wards-may-2020-boundaries-uk-bgc
# Converted to geojson manually from SHP because of GeoJSON download limits
wd20_filepath = source_files_path / "Electoral Wards May 2020.geojson"
# http://geoportal.statistics.gov.uk/datasets/local-authority-districts-may-2020-boundaries-uk-bgc
lad20_filepath = source_files_path / "Local Authorities May 2020.geojson"
# https://geoportal.statistics.gov.uk/datasets/counties-and-unitary-authorities-december-2019-boundaries-uk-bgc
ctyua19_filepath = source_files_path / "Counties_and_Unitary_Authorities__December_2019__Boundaries_UK_BGC.geojson"
# http://geoportal.statistics.gov.uk/datasets/ward-to-westminster-parliamentary-constituency-to-local-authority-district-december-2019-lookup-in-the-united-kingdom/data
wd_lad_map_filepath = source_files_path / "Electoral Wards and Local Authorities 2020.geojson"
# https://geoportal.statistics.gov.uk/datasets/lower-tier-local-authority-to-upper-tier-local-authority-december-2019-lookup-in-england-and-wales?where=LTLA19CD%20%3D%20%27E06000045%27
ltla_utla_map_filepath = source_files_path / "Lower_Tier_Local_Authority_to_Upper_Tier_Local_Authority__December_2019__Lookup_in_England_and_Wales.csv" # noqa: E501
ward_code_to_la_mapping = {
f["properties"]["WD19CD"]: f["properties"]["LAD19NM"]
for f in geojson.loads(wd_lad_map_filepath.read_text())["features"]
}
ward_code_to_la_id_mapping = {
f["properties"]["WD19CD"]: f["properties"]["LAD19CD"]
for f in geojson.loads(wd_lad_map_filepath.read_text())["features"]
}
# the mapping dict is empty for lower tier local authorities that are also upper tier (unitary authorities, etc)
ltla_utla_mapping_csv = csv.DictReader(ltla_utla_map_filepath.open())
la_code_to_cty_id_mapping = {
row['LTLA19CD']: row['UTLA19CD'] for row in ltla_utla_mapping_csv if row['LTLA19CD'] != row['UTLA19CD']
}
def add_countries():
dataset_id = 'ctry19'
dataset_geojson = geojson.loads(ctry19_filepath.read_text())
repo.insert_broadcast_area_library(
'ctry19',
name='Countries',
name_singular='country',
is_group=False,
)
areas_to_add = []
for feature in dataset_geojson["features"]:
f_id = 'ctry19-' + feature["properties"]['ctry19cd']
f_name = feature["properties"]['ctry19nm']
print() # noqa: T001
print(f_name) # noqa: T001
feature, simple_feature = (
polygons_and_simplified_polygons(feature["geometry"])
)
areas_to_add.append([
f_id, f_name,
dataset_id, None,
feature, simple_feature,
])
repo.insert_broadcast_areas(areas_to_add, keep_old_polygons)
def add_wards_local_authorities_and_counties():
dataset_name = "Local authorities"
dataset_name_singular = "local authority"
dataset_id = "wd20-lad20-ctyua19"
repo.insert_broadcast_area_library(
dataset_id,
name=dataset_name,
name_singular=dataset_name_singular,
is_group=True,
)
_add_electoral_wards(dataset_id)
_add_local_authorities(dataset_id)
_add_counties_and_unitary_authorities(dataset_id)
def _add_electoral_wards(dataset_id):
areas_to_add = []
for feature in geojson.loads(wd20_filepath.read_text())["features"]:
ward_code = feature["properties"]["wd20cd"]
ward_name = feature["properties"]["wd20nm"]
ward_id = "wd20-" + ward_code
print() # noqa: T001
print(ward_name) # noqa: T001
try:
la_id = "lad20-" + ward_code_to_la_id_mapping[ward_code]
feature, simple_feature = (
polygons_and_simplified_polygons(feature["geometry"])
)
areas_to_add.append([
ward_id, ward_name,
dataset_id, la_id,
feature, simple_feature
])
except KeyError:
print("Skipping", ward_code, ward_name) # noqa: T001
repo.insert_broadcast_areas(areas_to_add, keep_old_polygons)
def _add_local_authorities(dataset_id):
areas_to_add = []
for feature in geojson.loads(lad20_filepath.read_text())["features"]:
la_id = feature["properties"]["lad20cd"]
group_name = feature["properties"]["lad20nm"]
print() # noqa: T001
print(group_name) # noqa: T001
group_id = "lad20-" + la_id
feature, simple_feature = (
polygons_and_simplified_polygons(feature["geometry"])
)
ctyua_id = la_code_to_cty_id_mapping.get(la_id)
areas_to_add.append([
group_id,
group_name,
dataset_id,
'ctyua19-' + ctyua_id if ctyua_id else None,
feature,
simple_feature
])
repo.insert_broadcast_areas(areas_to_add, keep_old_polygons)
# counties and unitary authorities
def _add_counties_and_unitary_authorities(dataset_id):
areas_to_add = []
for feature in geojson.loads(ctyua19_filepath.read_text())['features']:
ctyua_id = feature["properties"]["ctyua19cd"]
group_name = feature["properties"]["ctyua19nm"]
la_id = 'lad20-' + ctyua_id
if repo.get_areas([la_id]):
continue
group_id = "ctyua19-" + ctyua_id
feature, simple_feature = (
polygons_and_simplified_polygons(feature["geometry"])
)
areas_to_add.append([
group_id, group_name,
dataset_id, None,
feature, simple_feature
])
repo.insert_broadcast_areas(areas_to_add, keep_old_polygons)
# cheeky global variable
keep_old_polygons = sys.argv[1:] == ['--keep-old-polygons']
print('keep_old_polygons: ', keep_old_polygons) # noqa: T001
repo = BroadcastAreasRepository()
if keep_old_polygons:
repo.delete_library_data()
else:
repo.delete_db()
repo.create_tables()
add_countries()
add_wards_local_authorities_and_counties()
most_detailed_polygons = formatted_list(
sorted(point_counts, reverse=True)[:5],
before_each='',
after_each='',
)
print( # noqa: T001
'\n'
'DONE\n'
f' Processed {len(point_counts):,} polygons.\n'
f' Highest point counts once simplifed: {most_detailed_polygons}\n'
)