问题：urllib.quote(xxx)运行后报错*** KeyError: u'\uxx'
原因：看下xxx类型：<type 'unicode'>，而urllib.quote(params)中的params就是字符串，只能猜测该字符串的编码不符合要求，所以对xxx进行编码
解决：urllib.quote(xxx.encode("utf-8"))或者urllib.quote(str(xxx))

示例如下：

>>> import urllib
>>> xxx = u'[{"test":"测试"}]'
>>> urllib.quote(xxx)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib.py", line 1298, in quote
    return ''.join(map(quoter, s))
KeyError: u'\u6d4b'
>>> type(xxx)
<type 'unicode'>
>>> urllib.quote(xxx.encode("utf-8"))
'%5B%7B%22test%22%3A%22%E6%B5%8B%E8%AF%95%22%7D%5D'
>>> urllib.quote(str(xxx))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeEncodeError: 'ascii' codec can't encode characters in position 10-11: ordinal not in range(128)
>>> import sys
>>> sys.setdefaultencoding('utf-8')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'setdefaultencoding'
>>> reload(sys)
<module 'sys' (built-in)>
>>> sys.setdefaultencoding('utf-8')
>>> urllib.quote(str(xxx))
'%5B%7B%22test%22%3A%22%E6%B5%8B%E8%AF%95%22%7D%5D'