JSON ValueError:未终止的字符串

Question

我的脚本可以工作，但有时会因以下错误而崩溃：

Traceback (most recent call last):
  File "planetafm.py", line 6, in <module>
    songs = json.loads(json_data)
  File "/usr/lib/python2.7/json/__init__.py", line 338, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python2.7/json/decoder.py", line 366, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python2.7/json/decoder.py", line 382, in raw_decode
    obj, end = self.scan_once(s, idx)
ValueError: Unterminated string starting at: line 1 column 32 (char 31)

例如，json导致：

rdsData({"now":{"id":"0052-55","title":"Summertime Sadness (Radio Mix)","artist":"Lana Del Rey","startDate":"2014-09-07 21:48:51","duration":"2014-09-07 21:48:51"}})

源代码：

import requests, json, re
url = "http://rds.eurozet.pl/reader/var/planeta.json"
response = requests.get(url)
json_data = re.match('rdsData((.*?))', response.content).group(1)
songs = json.loads(json_data)
print (songs['now']['artist'] + " - " + songs['now']['title']).encode('utf-8')

为什么json无效？如何解决此问题
谢谢你的回答！

Answer 1

您的regexp在文本中的右括号出现问题。您可以通过在regexp:中添加$来修复它

import requests, json, re
url = "http://rds.eurozet.pl/reader/var/planeta.json"
response = requests.get(url)
print response.content
json_data = re.match('rdsData((.*?))$', response.content).group(1)
print json_data
songs = json.loads(json_data)
print (songs['now']['artist'] + " - " + songs['now']['title']).encode('utf-8')

Answer 2

您的提取方法有缺陷；表达式终止于第一个)字符：

>>> import re
>>> import requests
>>> url = "http://rds.eurozet.pl/reader/var/planeta.json"
>>> r = requests.get(url)
>>> re.match('rdsData((.*?))', r.content).group(1)
'{"now":{"id":"0052-55","title":"Summertime Sadness (Radio Mix'

不使用正则表达式，只需使用str.partition()和str.rpartition():对值进行分区即可

url = "http://rds.eurozet.pl/reader/var/planeta.json"
response = requests.get(url)
json_data = response.content.partition('(')[-1].rpartition(')')[0]
songs = json.loads(json_data)

演示：

>>> json_data = r.content.partition('(')[-1].rpartition(')')[0]
>>> json.loads(json_data)['now']
{u'duration': u'2014-09-07 21:48:51', u'startDate': u'2014-09-07 21:48:51', u'artist': u'Lana Del Rey', u'id': u'0052-55', u'title': u'Summertime Sadness (Radio Mix)'}