Python 3.x 升级包失败

我想升级

ply

，所以我正在运行-

pip install ply --upgrade

我得到了错误（用**标记）——

如何解决此问题？

可能重复的

Collecting ply
  Using cached https://files.pythonhosted.org/packages/a3/58/35da89ee790598a0700ea49b2a66594140f44dec458c07e8e3d4979137fc/ply-3.11-py2.py3-none-any.whl
Installing collected packages: ply
  Found existing installation: ply 3.8
**Cannot uninstall 'ply'. It is a distutils installed project and thus we cannot accurately determine which files belong to it which would lead to only a partial uninstall.**
You are using pip version 10.0.1, however version 18.0 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.