由于项目的需求要计算整个海南的geohash编码及坐标，结合相关的开源项目实现本代码
import geohash as g
import json as j
由于python版本的geohash开源代码没有实现按照方向查找临近的栅格函数，所以自己实现一个函数
base32 = '0123456789bcdefghjkmnpqrstuvwxyz'
def adjacent(ghash,direction):
"""
Determines adjacent cell in given direction.
@param ghash - Cell to which adjacent cell is required.
@param direction - Direction from geohash (N/S/E/W).
@param returns {string} Geocode of adjacent cell.
"""
ghash=ghash.lower()
direction=direction.lower()
if direction not in 'nsew':
raise Exception("Invalid direction")
if len(ghash) == 0:
raise Exception("Invalid geohash")
neighbour = {
'n': [ 'p0r21436x8zb9dcf5h7kjnmqesgutwvy', 'bc01fg45238967deuvhjyznpkmstqrwx' ],
's': [ '14365h7k9dcfesgujnmqp0r2twvyx8zb', '238967debc01fg45kmstqrwxuvhjyznp' ],
'e': [ 'bc01fg45238967deuvhjyznpkmstqrwx', 'p0r21436x8zb9dcf5h7kjnmqesgutwvy' ],
'w': [ '238967debc01fg45kmstqrwxuvhjyznp', '14365h7k9dcfesgujnmqp0r2twvyx8zb' ]
}
border = {
'n': [ 'prxz', 'bcfguvyz' ],
's': [ '028b', '0145hjnp' ],
'e': [ 'bcfguvyz', 'prxz' ],
'w': [ '0145hjnp', '028b' ]
}
lastCh=ghash[-1]
parent=ghash[0:-1]
typee=len(ghash) % 2
if (lastCh in border[direction][typee]) and (parent != ''):
parent=adjacent(parent,direction)
return parent+base32[neighbour[direction][typee].index(lastCh)]
按照指定的范围遍历产生栅格，首先选择东北方向为开始点，然后往西求临近的栅格，直到到达西北方向的中止栅格。 东北方向的开始点和西北方向的中止点都往南移一栅格， 循环直到到达西南方向的中止栅格
geohash的长度对应的精度
Geohash length Cell width Cell height
1 ≤ 5,000km × 5,000km
2 ≤ 1,250km × 625km
3 ≤ 156km × 156km
4 ≤ 39.1km × 19.5km
5 ≤ 4.89km × 4.89km
6 ≤ 1.22km × 0.61km
7 ≤ 153m × 153m
8 ≤ 38.2m × 19.1m
9 ≤ 4.77m × 4.77m
10 ≤ 1.19m × 0.596m
11 ≤ 149mm × 149mm
12 ≤ 37.2mm × 18.6mm
level=4
#东北
neHash=g.encode(20.113826, 111.043138,level)
#西北
nwHash=g.encode(20.113826, 108.247665, level)
#西南
swHash=g.encode(18.082575, 108.247665, level)
#东南
seHash=g.encode(18.082575, 111.043138, level)
current = neHash
eastBound = neHash
westBound = nwHash
#返回给前端的格式
codedict=[[{'key':current},{'value':g.bbox(current)}]]
while True:
while current != westBound:
#由东往西搜索
current = adjacent(current,'w')
print(current)
codedict.append([{'key':current},{'value':g.bbox(current)}])
if current == swHash:
break
#西边往南移一格
westBound=adjacent(current,'s')
#东边往南移一格
eastBound=adjacent(eastBound,'s')
#当前位置设置为东边
current=eastBound
#open('./geohash.txt','w').write(j.dumps(codedict))