gla_boundary.py

"""
Pull Greater London Authority boundary definition (geojson) and derive the outer bounding box
"""

from operator import itemgetter
import json
import requests

r = requests.get('http://mapit.mysociety.org/area/2247.geojson')
coords = r.json()['coordinates'][0]

longitude = itemgetter(0)
latitude = itemgetter(1)

west = min([longitude(i) for i in coords])
north = max([latitude(i) for i in coords])
east = max([longitude(i) for i in coords])
south = min([latitude(i) for i in coords])

print(u'(({0}, {1}), ({2}, {3}))'.format(south, west, north, east))