greggs: add fetch_data

greggs.py

@@ -0,0 +1,39 @@
+#!/usr/bin/env python
+
+import overpy
+
+# brandname : overpass query filters
+BRANDS: dict[str, str] = {
+    "greggs": "[\"brand:wikidata\"=\"Q3403981\"]",
+}
+
+
+def fetch_data(brand: str) -> list[tuple[float | None, float | None]]:
+    api = overpy.Overpass()
+
+    filters = BRANDS[brand]
+    query = api.query(f"nwr{filters}; out center;")
+
+    result = []
+
+    for way in query.ways:
+        result.append((way.center_lat, way.center_lon))
+
+    for node in query.nodes:
+        result.append((node.lat, node.lon))
+
+    for (lat, lon) in result:
+        if (lat is None) or (lon is None):
+            raise ValueError("Item missing coords!")
+
+    return result
+
+
+def main():
+    print("Running query...")
+    greggs = fetch_data("greggs")
+    print(f"Query done - got {len(greggs)} Greggs!")
+
+
+if __name__ == "__main__":
+    main()