《Python网络编程》学习笔记--使用谷歌地理编码API获取一个JSON文档

Foundations of Python Network Programing，Third Edition 《python网络编程》，本书中的代码可在Github上搜索fopnp下载

本书的第一章中使用到了google地图的api来获取一个地址的经度和纬度，因为众所周知的原因会出现无法访问，我们需要使用代理访问

因此书上的代码需要根据实际情况来修改，我的电脑的代理地址为127.0.0.1:1080，下面放我的代码吧，可根据自己电脑的代理设置进行修改。

运行环境：Windows 10,Anaconda3,python3.6.3,Pycharm Edu 2017.3

调用库：

#search1.py

from pygeocoder import Geocoder

if __name__ == '__main__':
    a = Geocoder()
    a.proxy = "127.0.0.1:1080"
    address = '207 N. Definace St,Archbold,OH'
    print(a.geocode(address)[0].coordinates)

这里使用的是Geocoder中的proxy参数设置代理（需要先使用pip安装pygeocoder），因此必须先实例化，不能像书中一样直接print

应用层：

#search2.py

import requests

proxies = {"http": "http://127.0.0.1:1080", "https": "http://127.0.0.1:1080", }

def geocode(address):
    parameters = {'address': address, 'sensor': 'falise'}
    base = 'http://maps.googleapis.com/maps/api/geocode/json'
    response = requests.get(base, params=parameters, proxies=proxies)
    answer = response.json()
    print(answer['results'][0]['geometry']['location'])

if __name__ == '__main__':
    geocode('207 N. Defiance St,Archbold, OH')

这里使用了requests中的proxies参数设置代理

使用HTTP协议：

# search3.py

import http.client
import json
from urllib.parse import quote_plus

base = '/maps/api/geocode/json'

def geocode(address):
    path = '{}?address={}&sensor=false'.format(base, quote_plus(address))
    connection = http.client.HTTPSConnection('127.0.0.1', 1080)
    connection.set_tunnel('map.google.com')
    connection.request('GET', path)
    rawreply = connection.getresponse().read()
    reply = json.loads(rawreply.decode('utf-8'))
    print(reply['results'][0]['geometry']['location'])

if __name__ == '__main__':
    geocode('207 N. Defiance St,Archbold, OH')

这里会提示

Traceback (most recent call last):
  File "E:/Learn Python/Python网络编程/search3.py", line 21, in <module>
    geocode('207 N. Defiance St,Archbold, OH')
  File "E:/Learn Python/Python网络编程/search3.py", line 16, in geocode
    reply = json.loads(rawreply.decode('utf-8'))
  File "D:\Anaconda3\lib\json\__init__.py", line 354, in loads
    return _default_decoder.decode(s)
  File "D:\Anaconda3\lib\json\decoder.py", line 339, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "D:\Anaconda3\lib\json\decoder.py", line 357, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

Process finished with exit code 1

很明显报了一个json.decoder.JSONDecodeError的错误 说明没有能够正确访问，json decode失败

print(rawreply)发现rawreply返回的是这样的html文件

b'<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">\n
<TITLE>301 Moved</TITLE></HEAD><BODY>\n<H1>301 Moved</H1>\n
The document has moved\n
<A HREF="https://maps.google.com/maps/api/geocode/json?address=207+N.+Defiance+St%2CArchbold%2C+OH&sensor=false">here</A>.\r\n
</BODY>
</HTML>
\r\n'

返回了一个301错误，说明需要重定向这里我们使用的是HTTPS协议因此不会像浏览器一样直接重定向，感觉应该是google反爬虫的一种行为

因此我们使用正则表达式提取字符串（方法来自https://www.cnblogs.com/rj81/p/5933838.html），更改后代码如下

# search3.py

import http.client
import json
from urllib.parse import quote_plus
import re

base = '/maps/api/geocode/json'

def geocode(address):
    path = '{}?address={}&sensor=false'.format(base, quote_plus(address))
    connection = http.client.HTTPSConnection('127.0.0.1', 1080)
    connection.set_tunnel('map.google.com')
    connection.request('GET', path)
    rawreply = connection.getresponse().read().decode()
    newweb = re.findall(r"HREF=\"(.+?)\"", string=rawreply)
    # print(newweb)
    connection.request('GET', newweb[0])
    rawreply = connection.getresponse().read()
    # print(path)
    # print(rawreply)
    reply = json.loads(rawreply.decode('utf-8'))
    print(reply['results'][0]['geometry']['location'])

if __name__ == '__main__':
    geocode('207 N. Defiance St, Archbold, OH')

即可正确输出结果

{'lat': 41.5219645, 'lng': -84.3066496}

Process finished with exit code 0

这里需要注意的是 我一开始以为newweb是一个str，直接使用了connection.request('GET', newweb)

结果发现AttributeError: 'list' object has no attribute 'startswith'的错误，更改之后即可正常输出

直接使用Socket与谷歌地图通信：

设置代理的方法（转自http://www.jb51.net/article/50510.htm）

urllib2：

proxy_handler = urllib2.ProxyHandler({'http' : 'http://地址:端口'})
opener = urllib2.build_opener(proxy_handler, urllib2.HTTPHandler)
urllib2.install_opener(opener)

socket：

import socks, socket
socks.setdefaultproxy(socks.PROXY_TYPE_SOCKS5, "地址", 端口)
socket.socket = socks.socksocket

代码如下：

#search4.py
#!/usr/bin/env python3

import socket
import socks
from urllib.parse import quote_plus

request_text = """\
GET /maps/api/geocode/json?address={}&sensor=false HTTP/1.1\r\n\
Host: maps.google.com:80\r\n\
User-Agent: search4.py (Foundations of Python Network Programming)\r\n\
Connection: close\r\n\
\r\n\
"""

def geocode(address):
    socks.set_default_proxy(socks.PROXY_TYPE_SOCKS5, "127.0.0.1", 1080)
    socket.socket = socks.socksocket
    sock = socket.socket()
    sock.connect(('maps.google.com', 80))
    request = request_text.format(quote_plus(address))
    sock.sendall(request.encode('ascii'))
    raw_reply = b''
    while True:
        more = sock.recv(4096)
        if not more:
            break
        raw_reply += more
    print(raw_reply.decode('utf-8'))

if __name__ == '__main__':
    geocode('207 N. Defiance St, Archbold, OH')

运行输出：

HTTP/1.1  OK
Content-Type: application/json; charset=UTF-
Date: Fri,  Jan  :: GMT
Expires: Sat,  Jan  :: GMT
Cache-Control: public, max-age=
Access-Control-Allow-Origin: *
Server: mafe
X-XSS-Protection: ; mode=block
X-Frame-Options: SAMEORIGIN
Accept-Ranges: none
Vary: Accept-Language,Accept-Encoding
Connection: close

{
   "results" : [
      {
         "address_components" : [
            {
               "long_name" : "",
               "short_name" : "",
               "types" : [ "street_number" ]
            },
            {
               "long_name" : "North Defiance Street",
               "short_name" : "N Defiance St",
               "types" : [ "route" ]
            },
            {
               "long_name" : "Archbold",
               "short_name" : "Archbold",
               "types" : [ "locality", "political" ]
            },
            {
               "long_name" : "German Township",
               "short_name" : "German Township",
               "types" : [ "administrative_area_level_3", "political" ]
            },
            {
               "long_name" : "Fulton County",
               "short_name" : "Fulton County",
               "types" : [ "administrative_area_level_2", "political" ]
            },
            {
               "long_name" : "Ohio",
               "short_name" : "OH",
               "types" : [ "administrative_area_level_1", "political" ]
            },
            {
               "long_name" : "United States",
               "short_name" : "US",
               "types" : [ "country", "political" ]
            },
            {
               "long_name" : "",
               "short_name" : "",
               "types" : [ "postal_code" ]
            },
            {
               "long_name" : "",
               "short_name" : "",
               "types" : [ "postal_code_suffix" ]
            }
         ],
         "formatted_address" : "207 N Defiance St, Archbold, OH 43502, USA",
         "geometry" : {
            "bounds" : {
               "northeast" : {
                  "lat" : 41.521994,
                  "lng" : -84.30646179999999
               },
               "southwest" : {
                  "lat" : 41.521935,
                  "lng" : -84.30683739999999
               }
            },
            "location" : {
               "lat" : 41.5219645,
               "lng" : -84.3066496
            },
            "location_type" : "ROOFTOP",
            "viewport" : {
               "northeast" : {
                  "lat" : 41.5233134802915,
                  "lng" : -84.30530061970849
               },
               "southwest" : {
                  "lat" : 41.5206155197085,
                  "lng" : -84.3079985802915
               }
            }
         },
         "place_id" : "ChIJk4BHnIy0PYgRXbKj5GjFe_U",
         "types" : [ "premise" ]
      }
   ],
   "status" : "OK"
}

Process finished with exit code 0