geo-l1-tokyo-busstop-buffer

Rerun

# /// script
# requires-python = ">=3.12"
# dependencies = ["geopandas", "shapely", "pyproj"]
# ///

import geopandas as gpd

def main():
    input_file = "tokyo_connectors.geojson"
    output_file = "tokyo_stop_catchments.geoparquet"
    buffer_dist_m = 400

    # Load the connectors
    print(f"Reading {input_file}...")
    gdf = gpd.read_file(input_file)

    # Check if connector_id exists
    if 'connector_id' not in gdf.columns:
        raise ValueError("Column 'connector_id' not found in the input file.")

    # Ensure the CRS is defined. GeoJSON is usually EPSG:4326.
    if gdf.crs is None:
        print("CRS not found, assuming EPSG:4326")
        gdf.set_crs(epsg=4326, inplace=True)

    # Project to a metric CRS for accurate buffering.
    # For Tokyo, EPSG:3857 (Web Mercator) or a local UTM zone like EPSG:32654 (WGS 84 / UTM zone 54N) 
    # works. Given Tokyo's location, EPSG:6677 (JGD2011 / Japan Plane Rectangular CS VII) is very precise, 
    # but EPSG:3857 is generally fine for a 400m buffer unless high precision is required.
    # Let's use a local UTM zone for better accuracy in meters.
    # Tokyo is roughly 139.7E, 35.7N -> UTM 54N (EPSG:32654).
    
    print("Projecting to metric CRS for buffering...")
    gdf_metric = gdf.to_crs(epsg=32654)

    # Apply buffer
    print(f"Applying {buffer_dist_m}m buffer...")
    gdf_metric['geometry'] = gdf_metric.buffer(buffer_dist_m)

    # Project back to original CRS (EPSG:4326) if needed, 
    # though GeoParquet can store any CRS. 
    # Usually, it's good practice to keep the original CRS if the user wants to join with other layers.
    print(f"Projecting back to {gdf.crs}...")
    gdf_result = gdf_metric.to_crs(gdf.crs)

    # Keep only the required columns: geometry and connector_id
    # Note: gdf_result will have all columns from gdf, which is fine.
    # The prompt says "keep connector_id on every row", which it will.
    
    # Save to GeoParquet
    print(f"Saving to {output_file}...")
    gdf_result.to_parquet(output_file)
    print("Done!")

if __name__ == "__main__":
    main()

# /// script
# requires-python = ">=3.12"
# dependencies = ["geopandas", "shapely", "pyproj", "pyarrow"]
# ///

import geopandas as gpd

def main():
    input_file = "tokyo_connectors.geojson"
    output_file = "tokyo_stop_catchments.geoparquet"
    buffer_dist_m = 400

    # Load the connectors
    print(f"Reading {input_file}...")
    gdf = gpd.read_file(input_file)

    # Check if connector_id exists
    if 'connector_id' not in gdf.columns:
        raise ValueError("Column 'connector_id' not found in the input file.")

    # Ensure the CRS is defined. GeoJSON is usually EPSG:4326.
    if gdf.crs is None:
        print("CRS not found, assuming EPSG:4326")
        gdf.set_crs(epsg=4326, inplace=True)

    # Project to a metric CRS for accurate buffering.
    # Tokyo is roughly 139.7E, 35.7N -> UTM 54N (EPSG:32654).
    print("Projecting to metric CRS for buffering...")
    gdf_metric = gdf.to_crs(epsg=32654)

    # Apply buffer
    print(f"Applying {buffer_dist_m}m buffer...")
    gdf_metric['geometry'] = gdf_metric.buffer(buffer_dist_m)

    # Project back to original CRS
    print(f"Projecting back to {gdf.crs}...")
    gdf_result = gdf_metric.to_crs(gdf.crs)

    # Save to GeoParquet
    print(f"Saving to {output_file}...")
    gdf_result.to_parquet(output_file)
    print("Done!")

if __name__ == "__main__":
    main()

# /// script
# requires-python = ">=3.12"
# dependencies = ["geopandas", "pyarrow"]
# ///

import geopandas as gpd

def main():
    file_path = 'tokyo_stop_catchments.geoparquet'
    try:
        gdf = gpd.read_parquet(file_path)
        print("--- Head ---")
        print(gdf.head())
        print("\n--- CRS ---")
        print(gdf.crs)
        print("\n--- Columns ---")
        print(gdf.columns)
        print("\n--- Geometry Type ---")
        print(gdf.geometry.type.unique())
        print("\n--- Count ---")
        print(len(gdf))
    except Exception as e:
        print(f"Error: {e}")

if __name__ == "__main__":
    main()