code: def load_bathymetry(zip_file_url):
      """Read zip file from Natural Earth containing bathymetry shapefiles"""
      # Download and extract shapefiles
      import io
      import zipfile
  
      import requests
  
      r = requests.get(zip_file_url)
      z = zipfile.ZipFile(io.BytesIO(r.content))
      z.extractall("ne_10m_bathymetry_all/")
  
      # Read shapefiles, sorted by depth
      shp_dict = {}
      files = glob("ne_10m_bathymetry_all/*.shp")
      assert len(files) > 0
      files.sort()
      depths = []
      for f in files:
          depth = (
              "-" + f.split("_")[-1].split(".")[0]
          )  # depth from file name
          depths.append(depth)
          bbox = (90, -15, 160, 60)  # (x0, y0, x1, y1)
          nei = shpreader.Reader(f, bbox=bbox)
          shp_dict[depth] = nei
      depths = np.array(depths)[::-1]  # sort from surface to bottom
      return depths, shp_dict
  
file_path: cartopy/examples/lines_and_polygons/ocean_bathymetry.py
imports: from glob import glob
  import matplotlib
  import matplotlib.pyplot
  import numpy
  import cartopy.crs
  import cartopy.feature
  import cartopy.io.shapereader
label_desc: Use image node_id 1 for calling a global function with example usage: load_bathymetry(zip_file_url) and returns: depths,  shp_dict