File "/root/my_new_env/lib/python2.6/site-packages/scrapy/selector/dummysel.py", line 16, in _raise
raise RuntimeError("No selectors backend available. " \
exceptions.RuntimeError: No selectors backend available. Please install libxml2 or lxml
我安装了libxml2和lxml。有什么想法我会收到这个错误吗？