Generalise choropleth

src/lantmateriet/choropleth.py

@@ -0,0 +1,46 @@
+"""Choropleth module."""
+
+from pathlib import Path
+
+import geopandas as gpd
+from shapely import geometry, ops, polygonize
+
+
+def extract_choropleth(all_files: list[Path]):
+    """Extract Choropleth polygons from list of LineStrings."""
+    all_data = [
+        geo
+        for file in all_files
+        for geo in gpd.read_file(
+            file, use_arrow=True, engine="pyogrio"
+        ).geometry.to_list()
+    ]
+
+    return polygonize(ops.linemerge(geometry.MultiLineString(all_data)).geoms)
+
+
+def get_municipalities_choropleth(administrative_path: str, scb_path: str):
+    admin = Path(administrative_path)
+    scb = Path(scb_path)
+
+    all_files = [
+        admin / "04_riksgrans.geojson",
+        admin / "05_sjoterritoriets_grans_i_havet.geojson",
+        admin / "01_kommungrans.geojson",
+        admin / "02_lansgrans.geojson",
+    ]
+
+    return extract_choropleth(all_files)
+
+
+def get_regions_choropleth(administrative_path: str, scb_path: str):
+    admin = Path(administrative_path)
+    scb = Path(scb_path)
+
+    all_files = [
+        admin / "04_riksgrans.geojson",
+        admin / "05_sjoterritoriets_grans_i_havet.geojson",
+        admin / "02_lansgrans.geojson",
+    ]
+
+    return extract_choropleth(all_files)