使用Python解析JSON文件 - > google map api

Question

我试图在Python中开始使用JSON,但似乎我误解了JSON概念中的一些东西.我按照google api示例,工作正常.但是当我在JSON响应中将代码更改为较低级别时(如下所示,我尝试访问该位置),我收到以下代码的以下错误消息:

回溯(最近一次调用最后一次):
文件"geoCode.py",第11行,在
<module>
test = json.dumps中([s ['location']为s在jsonResponse ['results']],indent = 3)KeyError:'地点'

如何在python中访问JSON文件中的较低信息级别？我是否必须转到更高级别并搜索结果字符串？这对我来说似乎很奇怪？

这是我试图运行的代码:

import urllib, json
URL2 = "http://maps.googleapis.com/maps/api/geocode/json?address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&sensor=false"
googleResponse = urllib.urlopen(URL2);
jsonResponse = json.loads(googleResponse.read())
test = json.dumps([s['location'] for s in jsonResponse['results']], indent=3)
print test

Answer 1

理解jsonResponse格式的关键是将其打印出来:

import urllib, json
import pprint

URL2 = "http://maps.googleapis.com/maps/api/geocode/json?address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&sensor=false"

googleResponse = urllib.urlopen(URL2)
jsonResponse = json.loads(googleResponse.read())
pprint.pprint(jsonResponse)
# {u'results': [{u'address_components': [{u'long_name': u'1600',
#                                         u'short_name': u'1600',
#                                         u'types': [u'street_number']},
#                                        {u'long_name': u'Amphitheatre Pkwy',
#                                         u'short_name': u'Amphitheatre Pkwy',
#                                         u'types': [u'route']},
#                                        {u'long_name': u'Mountain View',
#                                         u'short_name': u'Mountain View',
#                                         u'types': [u'locality',
#                                                    u'political']},
#                                        {u'long_name': u'San Jose',
#                                         u'short_name': u'San Jose',
#                                         u'types': [u'administrative_area_level_3',
#                                                    u'political']},
#                                        {u'long_name': u'Santa Clara',
#                                         u'short_name': u'Santa Clara',
#                                         u'types': [u'administrative_area_level_2',
#                                                    u'political']},
#                                        {u'long_name': u'California',
#                                         u'short_name': u'CA',
#                                         u'types': [u'administrative_area_level_1',
#                                                    u'political']},
#                                        {u'long_name': u'United States',
#                                         u'short_name': u'US',
#                                         u'types': [u'country',
#                                                    u'political']},
#                                        {u'long_name': u'94043',
#                                         u'short_name': u'94043',
#                                         u'types': [u'postal_code']}],
#                u'formatted_address': u'1600 Amphitheatre Pkwy, Mountain View, CA 94043, USA',
#                u'geometry': {u'location': {u'lat': 37.4216227,
#                                            u'lng': -122.0840263},
#                              u'location_type': u'ROOFTOP',
#                              u'viewport': {u'northeast': {u'lat': 37.424770299999999,
#                                                           u'lng': -122.0808787},
#                                            u'southwest': {u'lat': 37.418475100000002,
#                                                           u'lng': -122.0871739}}},
#                u'types': [u'street_address']}],
#  u'status': u'OK'}

test = json.dumps([s['geometry']['location'] for s in jsonResponse['results']], indent=3)
print(test)
# [
#    {
#       "lat": 37.4216227, 
#       "lng": -122.0840263
#    }
# ]

1. jsonResponse 是一个字典.
2. jsonResponse['results'] 是一个dicts列表.
3. 循环通过循环为每次迭代for s in jsonResponse['results']分配 s一个dict.
4. s['geometry'] 是一个字典.
5. s['geometry']['location'] (最后!)包含纬度/经度字典.