ubuntu使用gevent报ImportError: No module named zope.interface解决

在ubuntu上用pip install grequest安装后，使用的时候发现总是gevent.py报ImportError: No module named zope.interface的错误

File "/usr/local/lib/python2.7/dist-packages/gevent/monkey.py", line 192, in ignores
    from gevent.events import DoNotPatch
  File "/usr/local/lib/python2.7/dist-packages/gevent/events.py", line 67, in <module>
    from zope.interface import Interface
ImportError: No module named interface

因为pip安装grequest时也会会安装gevent，zope.interface等，查了原因发现pip安装的路径下，没有此interface，但系统路径下有，所以可以软连接过去

cd /usr/local/lib/python2.7/dist-packages/zope
ln -s /usr/lib/python2.7/dist-packages/zope/interface/