python exceptions.UnicodeDecodeError：'ascii'编解码器无法解码字节0xa7

Question

I am using scrapy with python and I have this code in a python item pipline

def process_item(self, item, spider):
        import pdb; pdb.set_trace()
        ID = str(uuid.uuid5(uuid.NAMESPACE_DNS, item['link']))

I got this error :

        Traceback (most recent call last):
          File "C:\Python27\lib\site-packages\scrapy-0.20.2-py2.7.egg\scrapy\mid
dleware.py", line 62, in _process_chain
            return process_chain(self.methods[methodname], obj, *args)
          File "C:\Python27\lib\site-packages\scrapy-0.20.2-py2.7.egg\scrapy\uti
ls\defer.py", line 65, in process_chain
            d.callback(input)
          File "C:\Python27\lib\site-packages\twisted\internet\defer.py", line 3
82, in callback
            self._startRunCallbacks(result)
          File "C:\Python27\lib\site-packages\twisted\internet\defer.py", line 4
90, in _startRunCallbacks
            self._runCallbacks()
        --- <exception caught here> ---
          File "C:\Python27\lib\site-packages\twisted\internet\defer.py", line 5
77, in _runCallbacks
            current.result = callback(current.result, *args, **kw)
          File "General_Spider_code_version_2\pipelines.py", line 7, in process_
item
            ID = str(uuid.uuid5(uuid.NAMESPACE_DNS, item['link']))
          File "C:\Python27\lib\uuid.py", line 549, in uuid5
            hash = sha1(namespace.bytes + name).digest()
        exceptions.UnicodeDecodeError: 'ascii' codec can't decode byte 0xa7 in p
osition 1: ordinal not in range(128)

I tried to debug the item['link']

and this is the result

-> ID = str(uuid.uuid5(uuid.NAMESPACE_DNS, item['link']))
(Pdb) item['link']
u'http://dubai.dubizzle.com/property-for-rent/residential/apartmentflat/2014/4/6
/palm-jumeirah-abu-keibal-3-br-maid-partial-2/?back=ZHViYWkuZHViaXp6bGUuY29tL3By
b3BlcnR5LWZvci1yZW50L3Jlc2lkZW50aWFsL2FwYXJ0bWVudGZsYXQv&pos=1'
(Pdb)

as you see the item['link'] is unicode

Edit1

when I change the item['link'] to any other attribute like item['date'] the code works perfectly

Answer 1

使用.encode('utf-8')将unicode字符串编码为字节字符串，它应该工作：

str(uuid.uuid5(uuid.NAMESPACE_DNS, item['link'].encode('utf-8')))