Question

我正在尝试迭代JSON对象以导入数据，即标题和链接。我似乎无法访问超过:的内容。

JSON：

[
    {
        "title": "Baby (Feat. Ludacris) - Justin Bieber",
        "description": "Baby (Feat. Ludacris) by Justin Bieber on Grooveshark",
        "link": "http://listen.grooveshark.com/s/Baby+Feat+Ludacris+/2Bqvdq",
        "pubDate": "Wed, 28 Apr 2010 02:37:53 -0400",
        "pubTime": 1272436673,
        "TinyLink": "http://tinysong.com/d3wI",
        "SongID": "24447862",
        "SongName": "Baby (Feat. Ludacris)",
        "ArtistID": "1118876",
        "ArtistName": "Justin Bieber",
        "AlbumID": "4104002",
        "AlbumName": "My World (Part II);\nhttp://tinysong.com/gQsw",
        "LongLink": "11578982",
        "GroovesharkLink": "11578982",
        "Link": "http://tinysong.com/d3wI"
    },
    {
        "title": "Feel Good Inc - Gorillaz",
        "description": "Feel Good Inc by Gorillaz on Grooveshark",
        "link": "http://listen.grooveshark.com/s/Feel+Good+Inc/1UksmI",
        "pubDate": "Wed, 28 Apr 2010 02:25:30 -0400",
        "pubTime": 1272435930
    }
]

我尝试使用字典：

def getLastSong(user,limit):
    base_url = 'http://gsuser.com/lastSong/'
    user_url = base_url + str(user) + '/' + str(limit) + "/"
    raw = urllib.urlopen(user_url)
    json_raw= raw.readlines()
    json_object = json.loads(json_raw[0])

    #filtering and making it look good.
    gsongs = []
    print json_object
    for song in json_object[0]:   
        print song

此代码仅在:之前打印信息。（忽略Justin Bieber曲目：））

Answer 1

我相信你可能意味着：

for song in json_object:
    # now song is a dictionary
    for attribute, value in song.iteritems():
        print attribute, value # example usage

注意：对Python 3使用song.items而不是song.iteritems。

Answer 2

您加载JSON数据有点脆弱。而不是：

json_raw= raw.readlines()
json_object = json.loads(json_raw[0])

你真的应该这样做：

json_object = json.load(raw)

你不应该想到你得到的“JSON对象”。你有一个清单。该清单包含两个词组。 dicts包含各种键/值对，所有字符串。当你json_object[0]时，你要求列表中的第一个字典。当您使用for song in json_object[0]:迭代它时，您将遍历dict的键。因为这是你在迭代dict时得到的。如果您想访问与该词典中的键相关联的值，您可以使用，例如json_object[0][song]。

这些都不是特定于JSON的。它只是基本的Python类型，其基本操作在任何教程中都有介绍。

Answer 3

这个问题已经存在很长时间了，但是我想贡献我通常迭代JSON对象的方式。在下面的示例中，我展示了一个包含JSON的硬编码字符串，但JSON字符串可以很容易地来自Web服务或文件。

import json

def main():

    # create a simple JSON array
    jsonString = '{"key1":"value1","key2":"value2","key3":"value3"}'

    # change the JSON string into a JSON object
    jsonObject = json.loads(jsonString)

    # print the keys and values
    for key in jsonObject:
        value = jsonObject[key]
        print("The key and value are ({}) = ({})".format(key, value))

    pass

if __name__ == '__main__':
    main()

Answer 4

反序列化JSON后，你有一个python对象。使用常规对象方法。

在这种情况下，您有一个由词典组成的列表：

json_object[0].items()

json_object[0]["title"]

等

Answer 5

我会更像这样解决这个问题

import json
import urllib2

def last_song(user, limit):
    # Assembling strings with "foo" + str(bar) + "baz" + ... generally isn't 
    # as nice as using real string formatting. It can seem simpler at first, 
    # but leaves you less happy in the long run.
    url = 'http://gsuser.com/lastSong/%s/%d/' % (user, limit)

    # urllib.urlopen is deprecated in favour of urllib2.urlopen
    site = urllib2.urlopen(url)

    # The json module has a function load for loading from file-like objects, 
    # like the one you get from `urllib2.urlopen`. You don't need to turn 
    # your data into a string and use loads and you definitely don't need to 
    # use readlines or readline (there is seldom if ever reason to use a 
    # file-like object's readline(s) methods.)
    songs = json.load(site)

    # I don't know why "lastSong" stuff returns something like this, but 
    # your json thing was a JSON array of two JSON objects. This will 
    # deserialise as a list of two dicts, with each item representing 
    # each of those two songs.
    #
    # Since each of the songs is represented by a dict, it will iterate 
    # over its keys (like any other Python dict). 
    baby, feel_good = songs

    # Rather than printing in a function, it's usually better to 
    # return the string then let the caller do whatever with it. 
    # You said you wanted to make the output pretty but you didn't 
    # mention *how*, so here's an example of a prettyish representation
    # from the song information given.
    return "%(SongName)s by %(ArtistName)s - listen at %(link)s" % baby

Answer 6

对于Python 3，您必须解码从Web服务器返回的数据。例如，我将数据解码为utf8然后处理它：

 # example of json data object group with two values of key id
jsonstufftest = '{'group':{'id':'2','id':'3'}}
 # always set your headers
headers = {'User-Agent': 'Moz & Woz'}
 # the url you are trying to load and get json from
url = 'http://www.cooljson.com/cooljson.json'
 # in python 3 you can build the request using request.Request
req = urllib.request.Request(url,None,headers)
 # try to connect or fail gracefully
try:
    response = urllib.request.urlopen(req) # new python 3 code -jc
except:
    exit('could not load page, check connection')
 # read the response and DECODE
html=response.read().decode('utf8') # new python3 code
 # now convert the decoded string into real JSON
loadedjson = json.loads(html)
 # print to make sure it worked
print (loadedjson) # works like a charm
 # iterate through each key value
for testdata in loadedjson['group']:
    print (accesscount['id']) # should print 2 then 3 if using test json

如果你没有解码，你将在Python 3中获得字节与字符串错误。

Answer 7

通过迭代JSON，您可以使用：

json_object = json.loads(json_file)
for element in json_object: 
    for value in json_object['Name_OF_YOUR_KEY/ELEMENT']:
        print(json_object['Name_OF_YOUR_KEY/ELEMENT']['INDEX_OF_VALUE']['VALUE'])

Answer 8

如果您可以将json字符串存储在变量var x = window.matchMedia("(max-width: 600px)") x.addEventListener("change", () => { myFunction(x); });

中

CORS_SUPPORTS_CREDENTIALS = True

输出：

jsn_string

Answer 9

添加另一个解决方案（Python 3）-遍历目录中的json文件，并在每个文件上遍历所有对象并打印相关字段。

查看代码中的注释。

import os,json

data_path = '/path/to/your/json/files'  

# 1. Iterate over directory
directory = os.fsencode(data_path)
for file in os.listdir(directory):
    filename = os.fsdecode(file)
    # 2. Take only json files
    if filename.endswith(".json"):
        file_full_path=data_path+filename
        # 3. Open json file 
        with open(file_full_path, encoding='utf-8', errors='ignore') as json_data:
            data_in_file = json.load(json_data, strict=False)
            # 4. Iterate over objects and print relevant fields
            for json_object in data_in_file:
                print("ttl: %s, desc: %s" % (json_object['title'],json_object['description']) )

迭代JSON对象

9 个答案: