Downloads LAPD drone flight data

download_lapd_drone_flights.py

# /// script
# requires-python = ">=3.11"
# dependencies = [
#     "requests",
# ]
# ///

"""Download LAPD drone flight data from ArcGIS feature service."""

import json
import requests

SERVICE_URL = (
    "https://services7.arcgis.com/mnhQTdIYDA7UoY2l/arcgis/rest/services/"
    "5e6750a5-1bc9-4fb6-a6cf-8693f4d603ff-production/FeatureServer/0/query"
)
BATCH_SIZE = 2000
OUTPUT_FILE = "lapd_drone_flights.geojson"


def fetch_batch(offset: int) -> dict:
    params = {
        "where": "1=1",
        "outFields": "*",
        "outSR": "4326",
        "f": "geojson",
        "resultOffset": offset,
        "resultRecordCount": BATCH_SIZE,
    }
    resp = requests.get(SERVICE_URL, params=params, timeout=120)
    resp.raise_for_status()
    return resp.json()


def main():
    all_features = []
    offset = 0
    while True:
        print(f"Fetching records {offset}–{offset + BATCH_SIZE - 1}...")
        data = fetch_batch(offset)
        features = data.get("features", [])
        all_features.extend(features)
        print(f"  Got {len(features)} features (total: {len(all_features)})")
        if len(features) < BATCH_SIZE:
            break
        offset += BATCH_SIZE

    geojson = {
        "type": "FeatureCollection",
        "features": all_features,
    }
    with open(OUTPUT_FILE, "w") as f:
        json.dump(geojson, f)
    print(f"\nWrote {len(all_features)} features to {OUTPUT_FILE}")


if __name__ == "__main__":
    main()