37

我想这一定有一个简单的答案，但我很挣扎：我想获取一个 url（输出 json）并在 python 中的可用字典中获取数据。我被困在最后一步。

>>> import urllib2
>>> import simplejson
>>> req = urllib2.Request("http://vimeo.com/api/v2/video/38356.json", None, {'user-agent':'syncstream/vimeo'})
>>> opener = urllib2.build_opener()
>>> f = opener.open(req)
>>> f.read()             # this works
'[{"id":"38356","title":"Forgetfulness - Billy Collins Animated Poetry","description":"US Poet Laureate Billy Collins reads his poem ","url":"http:\\/\\/vimeo.com\\/38356","upload_date":"2006-01-24 15:21:03","thumbnail_small":"http:\\/\\/80.media.vimeo.com\\/d1\\/5\\/47\\/74\\/thumbnail-4774968.jpg","thumbnail_medium":"http:\\/\\/80.media.vimeo.com\\/d1\\/5\\/46\\/85\\/thumbnail-4685118.jpg","thumbnail_large":"http:\\/\\/images.vimeo.com\\/87\\/39\\/873998\\/873998_640x480.jpg","user_name":"smjwt","user_url":"http:\\/\\/vimeo.com\\/smjwt","user_portrait_small":"http:\\/\\/bitcast.vimeo.com\\/vimeo\\/portraits\\/defaults\\/d.30.jpg","user_portrait_medium":"http:\\/\\/bitcast.vimeo.com\\/vimeo\\/portraits\\/defaults\\/d.75.jpg","user_portrait_large":"http:\\/\\/bitcast.vimeo.com\\/vimeo\\/portraits\\/defaults\\/d.100.jpg","user_portrait_huge":"http:\\/\\/bitcast.vimeo.com\\/vimeo\\/portraits\\/defaults\\/d.300.jpg","stats_number_of_likes":"281","stats_number_of_plays":"9173","stats_number_of_comments":23,"duration":"112","width":"320","height":"240","tags":"poetry, poet, online poetry, famous poet, video poetry, modern poetry, famous poem, poetry sites, poetry websites, audio poetry, american poet, animation clips, american poetry, free poetry sites, animation art, free poetry, animated clips, poem, poet laureate"}]'
>>> simplejson.load(f)
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/usr/lib/python2.5/site-packages/django/utils/simplejson/__init__.py", line 298, in load
    parse_constant=parse_constant, **kw)
  File "/usr/lib/python2.5/site-packages/django/utils/simplejson/__init__.py", line 338, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python2.5/site-packages/django/utils/simplejson/decoder.py", line 326, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python2.5/site-packages/django/utils/simplejson/decoder.py", line 344, in raw_decode
    raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded

有什么想法我哪里出错了吗？

4

3 回答 3

42

尝试

f = opener.open(req)
simplejson.load(f)

没有先运行 f.read() 。当您运行 f.read() 时，文件句柄的内容会被吞掉，因此当您调用时不会留下任何内容simplejson.load(f)

于 2009-10-28T23:13:24.560 回答
10

第一行读取整个文件。然后第二行尝试从文件中读取更多内容，但没有任何内容：

>>> f.read()             # this works
blah blah blah
>>> simplejson.load(f)

要么省略 f.read() 行，要么保存读取的值，并在加载中使用它：

json = f.read()
simplejson.loads(json)
于 2009-10-28T23:17:30.560 回答
-7

还有一种更简单的方法——你根本不需要 simplejson。只要您将 true/false/null 设置为正确的值，Python 就可以使用 eval 语句将 json 解析为 dict/array。

# fetch the url
url = "https://api.twitter.com/1/users/lookup.json?user_id=6253282,18949452"
json = urllib2.urlopen(url).read()

# convert to a native python object
(true,false,null) = (True,False,None)
profiles = eval(json)
于 2012-01-15T03:15:44.450 回答