在Python中迭代和打印JSON对象

Question

我有一个Google Spreadsheet,我想用Python获取,然后通过JSON处理它.它已经完成了一半,在浏览Stackoverflow几个小时后,我认为是时候提问了.

例如,JSON文件的格式如下所示(来自https://developers.google.com/gdata/docs/json).

{
  "version": "1.0",
  "encoding": "UTF-8",
  "feed": {
    "xmlns": "http://www.w3.org/2005/Atom",
    "xmlns$openSearch": "http://a9.com/-/spec/opensearchrss/1.0/",
    "xmlns$gd": "http://schemas.google.com/g/2005",
    "xmlns$gCal": "http://schemas.google.com/gCal/2005",
    "id": {"$t": "..."},
    "updated": {"$t": "2006-11-12T21:25:30.000Z"},
    "title": {
      "type": "text",
      "$t": "Google Developer Events"
    },
    "subtitle": {
      "type": "text",
      "$t": "The calendar contains information about upcoming developer 
       conferences at which Google will be speaking, along with other 
       developer-related events."
    },
    "link": [{
      "rel": "...",
      "type": "application/atom+xml",
      "href": "..."
      },{
      "rel": "self",
      "type": "application/atom+xml",
      "href": "..."
    }],
    "author": [{
      "name": {"$t": "Google Developer Calendar"},
      "email": {"$t": "developer-calendar@google.com"}
    }],
    "generator":{
      "version": "1.0",
      "uri": "http://www.google.com/calendar",
      "$t": "Google Calendar"
    },
    "openSearch$startIndex": {"$t": "1"},
    "openSearch$itemsPerPage": {"$t": "25"},
    "gCal$timezone": {"value": "America/Los_Angeles"},

    "entry": [{
      "id": {"$t": "..."},
      "published": {"$t": "2006-11-12T21:25:30.000Z"},
      "updated": {"$t": "2006-11-12T21:25:30.000Z"},
      "category": [{
        "scheme": "...",
        "term": "..."
      }],
      "title":{
        "type": "text",
        "$t": "WebmasterWorld PubCon 2006: Google Developer Tools in General"
      },
      "content": {
        "type": "text",
        "$t": "Google is sponsoring at
          <a href=\"http://www.pubcon.com/\">WebmasterWorld PubCon 2006</a>.
          \n Come and visit us at the booth or join us for an evening demo
          reception where we will be talking \"5 ways to enhance your website
          with Google Code\". \n After all, \n it is Vegas, baby! See you soon."
      },
      "link": [{
        "rel": "alternate",
        "type": "text/html",
        "href": "...",
        "title": "alternate"
        },{
        "rel": "self",
        "type": "application/atom+xml",
        "href": "..."
      }],
      "author": [{
        "name": {"$t": "Google Developer Calendar"},
        "email": {"$t": "developer-calendar@google.com"}
      }],
      "gd$transparency": {"value": "http://schemas.google.com/g/2005#event.opaque"},
      "gd$eventStatus": {"value": "http://schemas.google.com/g/2005#event.confirmed"},
      "gd$comments": {"gd$feedLink": {"href": "..."}},
      "gCal$sendEventNotifications": {"value": "true"},
      "gd$when": [{
        "startTime": "2006-11-15",
        "endTime": "2006-11-17",
        "gd$reminder": [{"minutes": "10"}]
      }],
      "gd$where": [{"valueString": "3150 Paradise Road,Las Vegas,NV 89109"}]},
    }]
  }
}

我的Python代码如下:

import requests, json
r = requests.get('link-to-google-spreadsheet-json')
j = r.json()

测试JSON文件的顶级层次结构输出如下:

>>> print j["version"]
1.0

但迭代对象,如下所示:

for feed in j["feed"]:
    for entry in feed["entry"]:
        for title in entry["title"]:
            print title["$t"]
        print
    print

给我以下错误:

Traceback (most recent call last):
File "<console>", line 2, in <module>
TypeError: string indices must be integers.

听起来它想要从字符串中打印一个字母,只要我给出索引号.那么如何解析JSON以便正确输出我想要的内容(例如feed - > entry - > title - > $ t)？

Answer 1

j ['feed']是一本字典.您的代码应如下所示:

for entry in j['feed']['entry']:
    print entry['title']['$t']