通过url获取json数据并在python (simplejson)中使用

I imagine this must have a simple answer, but I am struggling: I want to take a url (which outputs json) and get the data in a usable dictionary in python. I am stuck on the last step.

我想这一定有一个简单的答案，但我很纠结:我想获取一个url(输出json)，并在python中的一个可用字典中获取数据。我被困在最后一步了。

>>> 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

Any ideas where I am going wrong?

你知道我哪里出错了吗?

3 个解决方案

#1

Try

试一试

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

without running f.read() first. When you run f.read(), the filehandle's contents are slurped so there is nothing left when your call simplejson.load(f)

没有运行f.read()。当您运行f.read()时，文件句柄的内容被发出声音，所以当您调用simplejson.load(f)时，什么都没有留下。

#2

The first line reads the entire file. The second line then tries to read more from the file, but there's nothing left:

第一行读取整个文件。然后第二行尝试从文件中读取更多信息，但是什么都没有了:

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

Either just omit the f.read() line, or save the value from read, and use it in loads:

或者省略f.read()行，或者从read中保存值，然后在load中使用:

json = f.read()
simplejson.loads(json)

#3

-7

There's an even easier way - you dont need simplejson at all. Python can parse json into a dict/array using the eval statement as long as you set true/false/null to the right values.

还有一种更简单的方法——根本不需要simplejson。只要将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/数组。

# 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)

#1

Try

试一试

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