您应该尝试的第一件事是:

The first thing you should try is:

sudo pip uninstall pip

在许多不起作用的环境中.因此，鉴于缺乏有关该问题的信息，我最终从/usr/local/bin 中手动删除了 pip.

On many environments that doesn't work. So given the lack of info on that problem, I ended up removing pip manually from /usr/local/bin.