title: Why I can't use urlencode to encode json format data?
body: <p>I have a problem about urlencode in python 2.7:</p>
  
  <pre><code>&gt;&gt;&gt; import urllib
  &gt;&gt;&gt; import json
  &gt;&gt;&gt; urllib.urlencode(json.dumps({'title':"hello world！",'anonymous':False,'needautocategory':True}))
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
    File "/usr/local/lib/python2.7/urllib.py", line 1280, in urlencode
      raise TypeError
  TypeError: not a valid non-string sequence or mapping object
  </code></pre>