error when using scrapy startproject in python2.7

I successfully installed Scrapy under python2.7,and when i created a new project using scrapy startproject example,an exception raised:

Traceback (most recent call last):
  File "/usr/local/bin/scrapy", line 5, in <module>
    from pkg_resources import load_entry_point
  File "/usr/local/lib/python3.4/site-packages/pkg_resources.py", line 2697, in <module>
    working_set.require(__requires__)
  File "/usr/local/lib/python3.4/site-packages/pkg_resources.py", line 669, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/usr/local/lib/python3.4/site-packages/pkg_resources.py", line 572, in resolve
    raise DistributionNotFound(req)
pkg_resources.DistributionNotFound: six>=1.5.2

any ideas?thanks in advance!