我正在尝试迭代 JSON 对象来导入数据,即标题和链接。我似乎无法理解
:
之后的内容。
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
此代码仅打印
:
之前的信息。
(忽略贾斯汀·比伯的曲目:))
我相信你的意思可能是:
from __future__ import print_function
for song in json_object:
# now song is a dictionary
for attribute, value in song.items():
print(attribute, value) # example usage
注意:如果在 Python 2 中,您可以使用
song.iteritems
代替 song.items
。
您加载的 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)
您不应该将获得的内容视为“JSON 对象”。你所拥有的是一个清单。该列表包含两个字典。字典包含各种键/值对,所有字符串。当您执行
json_object[0]
时,您正在请求列表中的第一个字典。当您使用 for song in json_object[0]:
对其进行迭代时,您将迭代字典的键。因为这就是你迭代字典时得到的结果。如果您想访问与该字典中的键关联的值,您可以使用,例如,json_object[0][song]
。
这些都不是 JSON 特有的。这只是基本的 Python 类型,其基本操作在任何教程中都有介绍。
这个问题已经存在很长时间了,但我想贡献一下我通常如何迭代 JSON 对象。 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 字符串也可以轻松来自 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()
反序列化 JSON 后,你就有了一个 python 对象。使用常规对象方法。
在本例中,您有一个由字典组成的列表:
json_object[0].items()
json_object[0]["title"]
等
我会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
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
如果不解码,Python 3 中将出现字节与字符串错误。
要迭代 JSON,你可以使用这个:
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'])
添加另一个解决方案(Python 3) - 迭代目录中的 json 文件,并在每个文件上迭代所有对象并打印相关字段。
请参阅代码中的注释。
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']) )
如果可以将json字符串存储在变量中
jsn_string
import json
jsn_list = json.loads(json.dumps(jsn_string))
for lis in jsn_list:
for key,val in lis.items():
print(key, val)
输出:
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);
http://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
您也可以使用 pandas:
import pandas as pd
# Load json file
jsonlist = pd.read_json("listfile.json") # your json file
jsonlist.head()
# Loop process
for key in jsonlist:
print(jsonlist['title'], jsonlist['description')