scrapy shell [url] TypeError: 'float' object is not iterable

• python 3.6
• scrapy 1.1.1
• twisted 17.1.0

运行scrapy shell [URL]，得到TypeError：

(scrapy) D:\>scrapy shell "www.python.com"
2017-03-08 12:12:05 [scrapy] INFO: Scrapy 1.1.1 started (bot: scrapybot)
2017-03-08 12:12:05 [scrapy] INFO: Overridden settings: {'DUPEFILTER_CLASS': 'scrapy.dupefilters.BaseDupeFilter', 'LOGSTATS_INTERVAL': 0}
2017-03-08 12:12:05 [scrapy] INFO: Enabled extensions:
['scrapy.extensions.corestats.CoreStats',
 'scrapy.extensions.telnet.TelnetConsole']
2017-03-08 12:12:05 [scrapy] INFO: Enabled downloader middlewares:
['scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware',
 'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware',
 'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware',
 'scrapy.downloadermiddlewares.retry.RetryMiddleware',
 'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware',
 'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware',
 'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware',
 'scrapy.downloadermiddlewares.redirect.RedirectMiddleware',
 'scrapy.downloadermiddlewares.cookies.CookiesMiddleware',
 'scrapy.downloadermiddlewares.chunked.ChunkedTransferMiddleware',
 'scrapy.downloadermiddlewares.stats.DownloaderStats']
2017-03-08 12:12:05 [scrapy] INFO: Enabled spider middlewares:
['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware',
 'scrapy.spidermiddlewares.offsite.OffsiteMiddleware',
 'scrapy.spidermiddlewares.referer.RefererMiddleware',
 'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware',
 'scrapy.spidermiddlewares.depth.DepthMiddleware']
2017-03-08 12:12:05 [scrapy] INFO: Enabled item pipelines:
[]
2017-03-08 12:12:05 [scrapy] DEBUG: Telnet console listening on 127.0.0.1:6023
2017-03-08 12:12:05 [scrapy] INFO: Spider opened
Traceback (most recent call last):
  File "d:\Anaconda3\envs\scrapy\Scripts\scrapy-script.py", line 5, in 
    sys.exit(scrapy.cmdline.execute())
  File "d:\Anaconda3\envs\scrapy\lib\site-packages\scrapy\cmdline.py", line 142, in execute
    _run_print_help(parser, _run_command, cmd, args, opts)
  File "d:\Anaconda3\envs\scrapy\lib\site-packages\scrapy\cmdline.py", line 88, in _run_print_help
    func(*a, **kw)
  File "d:\Anaconda3\envs\scrapy\lib\site-packages\scrapy\cmdline.py", line 149, in _run_command
    cmd.run(args, opts)
  File "d:\Anaconda3\envs\scrapy\lib\site-packages\scrapy\commands\shell.py", line 71, in run
    shell.start(url=url)
  File "d:\Anaconda3\envs\scrapy\lib\site-packages\scrapy\shell.py", line 47, in start
    self.fetch(url, spider)
  File "d:\Anaconda3\envs\scrapy\lib\site-packages\scrapy\shell.py", line 112, in fetch
    reactor, self._schedule, request, spider)
  File "d:\Anaconda3\envs\scrapy\lib\site-packages\twisted\internet\threads.py", line 122, in blockingCallFromThread
    result.raiseException()
  File "d:\Anaconda3\envs\scrapy\lib\site-packages\twisted\python\failure.py", line 372, in raiseException
    raise self.value.with_traceback(self.tb)
TypeError: 'float' object is not iterable

解决： 我在台式机上的虚拟环境为python3.6，scrapy1.1.1，同样可以运行，于是看了下返回的错误发生在twisted，检查了一下，台式机上是twisted16.6.0，然后应该是最近升级了一次，笔记本自动安装的是17.1.0的版本，然后执行

conda install twisted==16.6.0

然后DOWNGRADE，yes，再次运行scrapy shell “www.python.org”，可以成功进入ipython。

最后查github上的issue list也发现了同样的问题。
scrapy/issues/2606