AttributeError: module 'pip' has no attribute 'main'如何解决？

报错信息：

Traceback (most recent call last):
  File "C:\Program Files\JetBrains\PyCharm 2017.3.1\helpers\packaging_tool.py", line 192, in main
    retcode = do_install(pkgs)
  File "C:\Program Files\JetBrains\PyCharm 2017.3.1\helpers\packaging_tool.py", line 109, in do_install
    return pip.main(['install'] + pkgs)
AttributeError: module 'pip' has no attribute 'main'

pip10.0没有main(),考虑降个版本：python -m pip install –upgrade pip==9.0.3