cannot import name 'main' 解决方案

error description:

pip3 install numpy
Traceback (most recent call last):
  File "/usr/bin/pip3", line 9, in <module>
    from pip import main
ImportError: cannot import name 'main'

You must have inadvertently upgraded your system pip (probably through something like sudo pip install pip --upgrade)

pip 10.x adjusts where its internals are situated. The pip3 command you're seeing is one provided by your package maintainer (presumably debian based here?) and is not a file managed by pip.

You can read more about this on pip's issue tracker

You'll probably want to not upgrade your system pip and instead use a virtualenv.

To recover the pip3 binary you'll need to

 sudo python3 -m pip uninstall pip && sudo apt install python3-pip --reinstall

If you want to continue in "unsupported territory" (upgrading a system package outside of the system package manager), you can probably get away with python3 -m pip ... instead of pip3.