判断百度某一经纬度的地图颜色值python

 from PIL import Image
 import MySQLdb
 import os
 import urllib
 import time
 from multiprocessing.dummy import Pool as ThreadPool 

 def gaidu_is_water((latitude,longitude)):
     while True:
         try:
             ll = longitude + ',' + latitude
             url = "http://api.map.baidu.com/staticimage?center="+ll+"&zoom=18&width=1&height=1"
             data = urllib.urlretrieve(url, ll)
             im = Image.open(ll)
             rgb_im = im.convert('RGB')
             print rgb_im.getpixel((0, 0))
             if rgb_im.getpixel((0, 0)) in [(167, 192, 224),(104, 137, 167),(153, 183, 219)]:
                 # print 'is water'
                 flag = 1
             else:
                 flag = 0
                 # print 'not water'
             # print ll,'ok'
             break
         except Exception, e:
             print e
             time.sleep(5)
             continue

 if __name__ == '__main__':
     print gaidu_is_water('114.24419,22.332689')
     pool = ThreadPool(20)
     results = pool.map(gaidu_is_water, lls)
     pool.close()
     pool.join()