This commit is contained in:
Andras Schmelczer 2026-05-31 20:20:41 +01:00
parent 8688b7475e
commit e8345cbdc1
40 changed files with 1980 additions and 904 deletions

View file

@ -1,10 +1,12 @@
import json
import shutil
from collections import defaultdict
from pathlib import Path
from pyproj import Transformer
from shapely import make_valid
from shapely.geometry import MultiPolygon, Polygon
from shapely import make_valid, set_precision
from shapely.geometry import MultiPolygon, Polygon, mapping, shape
from shapely.ops import transform as transform_geometry
from shapely.ops import unary_union
from tqdm import tqdm
@ -18,49 +20,47 @@ def _get_to_wgs84():
return _to_wgs84
def _largest_polygonal(geom) -> Polygon | None:
if geom is None or geom.is_empty:
return None
if not geom.is_valid:
geom = make_valid(geom)
if geom.geom_type == "Polygon":
return geom
if geom.geom_type == "MultiPolygon":
return max(geom.geoms, key=lambda g: g.area)
if geom.geom_type == "GeometryCollection":
polygons = [
polygon
for part in geom.geoms
if (polygon := _largest_polygonal(part)) is not None
]
if polygons:
return max(polygons, key=lambda g: g.area)
return None
def to_wgs84_geojson(
geom: Polygon | MultiPolygon, tolerance: float = 1.0
) -> dict | None:
"""Simplify geometry in BNG, convert to WGS84, return GeoJSON dict."""
if geom.is_empty:
geom = _largest_polygonal(geom)
if geom is None:
return None
simplified = geom.simplify(tolerance, preserve_topology=True)
if simplified.is_empty:
simplified = _largest_polygonal(simplified)
if simplified is None:
return None
transformer = _get_to_wgs84()
def transform_ring(coords):
xs, ys = zip(*coords)
lons, lats = transformer.transform(list(xs), list(ys))
return [(round(lon, 6), round(lat, 6)) for lon, lat in zip(lons, lats)]
def transform_polygon(poly):
exterior = transform_ring(poly.exterior.coords)
holes = [transform_ring(h.coords) for h in poly.interiors]
return [exterior] + holes
# Force single Polygon — postcodes are contiguous delivery routes
if simplified.geom_type == "MultiPolygon":
simplified = max(simplified.geoms, key=lambda g: g.area)
elif simplified.geom_type == "GeometryCollection":
polys = [
g for g in simplified.geoms if g.geom_type in ("Polygon", "MultiPolygon")
]
if not polys:
return None
simplified = max(polys, key=lambda g: g.area)
if simplified.geom_type == "MultiPolygon":
simplified = max(simplified.geoms, key=lambda g: g.area)
if simplified.geom_type != "Polygon" or simplified.is_empty:
wgs84 = transform_geometry(transformer.transform, simplified)
wgs84 = set_precision(wgs84, 0.000001, mode="valid_output")
wgs84 = _largest_polygonal(wgs84)
if wgs84 is None:
return None
return {
"type": "Polygon",
"coordinates": transform_polygon(simplified),
}
return mapping(wgs84)
def _fill_holes(geom):
@ -132,7 +132,11 @@ def write_district_geojson(
) -> int:
"""Group postcodes by district, write GeoJSON files. Returns file count."""
units_dir = output_dir / "units"
units_dir.mkdir(parents=True, exist_ok=True)
tmp_units_dir = output_dir / "units.tmp"
output_dir.mkdir(parents=True, exist_ok=True)
if tmp_units_dir.exists():
shutil.rmtree(tmp_units_dir)
tmp_units_dir.mkdir(parents=True)
by_district: dict[str, list[tuple[str, Polygon | MultiPolygon]]] = defaultdict(list)
for pc, geom in postcodes.items():
@ -141,14 +145,23 @@ def write_district_geojson(
by_district[district].append((pc, geom))
file_count = 0
seen_postcodes: set[str] = set()
for district, entries in tqdm(
sorted(by_district.items()), desc="Writing GeoJSON", unit="file"
):
features = []
for pc, geom in sorted(entries, key=lambda x: x[0]):
if pc in seen_postcodes:
raise ValueError(f"Duplicate postcode boundary feature: {pc}")
seen_postcodes.add(pc)
geojson_geom = to_wgs84_geojson(geom)
if geojson_geom is None:
continue
raise ValueError(f"Postcode boundary collapsed to empty geometry: {pc}")
written_geom = shape(geojson_geom)
if written_geom.is_empty or not written_geom.is_valid:
raise ValueError(
f"Invalid postcode boundary geometry after output: {pc}"
)
mapit_code = pc.replace(" ", "")
features.append(
{
@ -165,9 +178,12 @@ def write_district_geojson(
continue
collection = {"type": "FeatureCollection", "features": features}
out_path = units_dir / f"{district}.geojson"
out_path = tmp_units_dir / f"{district}.geojson"
with open(out_path, "w") as f:
json.dump(collection, f, separators=(",", ":"))
file_count += 1
if units_dir.exists():
shutil.rmtree(units_dir)
tmp_units_dir.replace(units_dir)
return file_count

View file

@ -3,6 +3,8 @@
Each test targets a specific bug or edge case identified during code review.
"""
import json
import numpy as np
import polars as pl
import pytest
@ -11,7 +13,12 @@ from shapely.ops import unary_union
from .oa_boundaries import parse_gpkg_geometry
from .greenspace import subtract_greenspace
from .output import _fill_holes, merge_fragments, to_wgs84_geojson
from .output import (
_fill_holes,
merge_fragments,
to_wgs84_geojson,
write_district_geojson,
)
from .process_oa import _extract_polygonal, process_oa
from .uprn import get_oa_uprns, load_uprns
from .voronoi import _equal_split_fallback, compute_voronoi_regions
@ -154,6 +161,7 @@ class TestWhitespacePostcodes:
"pcds": ["AA1 1AA", "AA1 1AB"],
"east1m": [500010, 500030],
"north1m": [180010, 180020],
"oa21cd": ["E00000001", "E00000001"],
"doterm": ["2020-01-01", None],
"ctry25cd": ["E92000001", "E92000001"],
}
@ -165,6 +173,65 @@ class TestWhitespacePostcodes:
assert loaded_df["PCDS"].to_list() == ["AA1 1AB"]
def test_arcgis_filters_to_active_english_postcodes(self, tmp_path):
uprns = pl.DataFrame(
{
"GRIDGB1E": [500010, 500020],
"GRIDGB1N": [180010, 180020],
"PCDS": ["AA1 1AA", "CF1 1AA"],
"OA21CD": ["E00000001", "E00000001"],
}
)
uprn_path = tmp_path / "uprn.parquet"
uprns.write_parquet(uprn_path)
arcgis = pl.DataFrame(
{
"pcds": ["AA1 1AA", "CF1 1AA"],
"east1m": [500010, 300010],
"north1m": [180010, 220010],
"oa21cd": ["E00000001", "W00000001"],
"doterm": [None, None],
"ctry25cd": ["E92000001", "W92000004"],
}
)
arcgis_path = tmp_path / "arcgis.parquet"
arcgis.write_parquet(arcgis_path)
loaded_df, _offsets = load_uprns(uprn_path, arcgis_path)
assert loaded_df["PCDS"].to_list() == ["AA1 1AA"]
def test_arcgis_adds_centroid_seed_for_active_postcode_without_uprn(self, tmp_path):
uprns = pl.DataFrame(
{
"GRIDGB1E": [500010],
"GRIDGB1N": [180010],
"PCDS": ["AA1 1AA"],
"OA21CD": ["E00000001"],
}
)
uprn_path = tmp_path / "uprn.parquet"
uprns.write_parquet(uprn_path)
arcgis = pl.DataFrame(
{
"pcds": ["AA1 1AA", "BB1 1BB"],
"east1m": [500010, 510000],
"north1m": [180010, 190000],
"oa21cd": ["E00000001", "E00000002"],
"doterm": [None, None],
"ctry25cd": ["E92000001", "E92000001"],
}
)
arcgis_path = tmp_path / "arcgis.parquet"
arcgis.write_parquet(arcgis_path)
loaded_df, offsets = load_uprns(uprn_path, arcgis_path)
assert set(loaded_df["PCDS"].to_list()) == {"AA1 1AA", "BB1 1BB"}
points, postcodes = get_oa_uprns(loaded_df, offsets, "E00000002")
assert postcodes == ["BB1 1BB"]
assert points.tolist() == [[510000.0, 190000.0]]
# ---------------------------------------------------------------------------
# Bug 3: Voronoi deduplication is first-seen-wins
@ -450,7 +517,9 @@ class TestProcessOAInspireParcelAssignment:
)
postcodes = ["A", "B"]
fragments = process_oa(oa_geom, points, postcodes, inspire_candidates=[left, right])
fragments = process_oa(
oa_geom, points, postcodes, inspire_candidates=[left, right]
)
frag_dict = dict(fragments)
assert "A" in frag_dict and "B" in frag_dict
@ -494,7 +563,9 @@ class TestProcessOAInspireParcelAssignment:
)
postcodes = ["A", "B"]
fragments = process_oa(oa_geom, points, postcodes, inspire_candidates=[left, right])
fragments = process_oa(
oa_geom, points, postcodes, inspire_candidates=[left, right]
)
frag_dict = dict(fragments)
assert "A" in frag_dict and "B" in frag_dict
@ -539,7 +610,9 @@ class TestProcessOAInspireParcelAssignment:
)
postcodes = ["A", "B"]
fragments = process_oa(oa_geom, points, postcodes, inspire_candidates=[straddling])
fragments = process_oa(
oa_geom, points, postcodes, inspire_candidates=[straddling]
)
for _, geom in fragments:
assert geom.difference(oa_geom).area < 0.01
@ -651,6 +724,22 @@ class TestToWgs84Geojson:
assert lon_dp <= 6, f"Longitude {lon_s} has {lon_dp} decimal places"
assert lat_dp <= 6, f"Latitude {lat_s} has {lat_dp} decimal places"
def test_write_district_geojson_replaces_stale_units(self, tmp_path):
stale_units = tmp_path / "units"
stale_units.mkdir()
(stale_units / "ZZ1.geojson").write_text(
json.dumps({"type": "FeatureCollection", "features": []})
)
file_count = write_district_geojson(
{"AA1 1AA": box(530000, 180000, 530100, 180100)}, tmp_path
)
assert file_count == 1
assert not (stale_units / "ZZ1.geojson").exists()
written = json.loads((stale_units / "AA1.geojson").read_text())
assert written["features"][0]["properties"]["postcodes"] == "AA1 1AA"
# ---------------------------------------------------------------------------
# Edge case: parse_gpkg_geometry rejects unknown envelope types

View file

@ -13,6 +13,33 @@ def _canonical_postcode_expr(name: str) -> pl.Expr:
return pl.col(name).str.strip_chars().str.to_uppercase()
def _active_english_arcgis_postcodes(arcgis_path: Path) -> pl.LazyFrame:
return (
pl.read_parquet(
arcgis_path,
columns=["pcds", "east1m", "north1m", "oa21cd", "ctry25cd", "doterm"],
)
.lazy()
.filter(pl.col("ctry25cd") == "E92000001")
.filter(pl.col("doterm").cast(pl.Utf8).is_null())
.select(
_canonical_postcode_expr("pcds").alias("PCDS"),
pl.col("east1m").cast(pl.Float64).alias("GRIDGB1E"),
pl.col("north1m").cast(pl.Float64).alias("GRIDGB1N"),
pl.col("oa21cd").alias("OA21CD"),
)
.filter(
pl.col("PCDS").is_not_null()
& (pl.col("PCDS") != "")
& pl.col("GRIDGB1E").is_not_null()
& pl.col("GRIDGB1N").is_not_null()
& pl.col("OA21CD").is_not_null()
& pl.col("OA21CD").str.starts_with("E")
)
.unique("PCDS")
)
def load_uprns(
uprn_path: Path, arcgis_path: Path | None = None
) -> tuple[pl.DataFrame, dict[str, tuple[int, int]]]:
@ -25,6 +52,7 @@ def load_uprns(
print("Loading UPRN lookup...")
mapping = None
active_postcode_points = None
if arcgis_path is not None:
mapping = (
build_postcode_mapping(arcgis_path)
@ -34,6 +62,7 @@ def load_uprns(
)
.unique("old_postcode")
)
active_postcode_points = _active_english_arcgis_postcodes(arcgis_path)
# Sort via streaming sink to avoid polars doubling memory during in-memory sort
with tempfile.NamedTemporaryFile(
@ -51,11 +80,21 @@ def load_uprns(
if mapping is not None and mapping.height > 0:
uprns = (
uprns.join(mapping.lazy(), left_on="PCDS", right_on="old_postcode", how="left")
uprns.join(
mapping.lazy(), left_on="PCDS", right_on="old_postcode", how="left"
)
.with_columns(pl.coalesce("new_postcode", "PCDS").alias("PCDS"))
.select("GRIDGB1E", "GRIDGB1N", "PCDS", "OA21CD")
)
if active_postcode_points is not None:
active_postcodes = active_postcode_points.select("PCDS").unique()
uprns = uprns.join(active_postcodes, on="PCDS", how="semi")
missing_active = active_postcode_points.join(
uprns.select("PCDS").unique(), on="PCDS", how="anti"
).select("GRIDGB1E", "GRIDGB1N", "PCDS", "OA21CD")
uprns = pl.concat([uprns, missing_active], how="vertical_relaxed")
uprns.sort("OA21CD").sink_parquet(tmp_path)
release_memory()