pip3 -V
Traceback (most recent call last):
  File "/usr/local/bin/pip3", line 7, in <module>
    from pip._internal import main
ModuleNotFoundError: No module named ‘pip._internal‘

於是我們換個方式重新安裝pip3

curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
python3 get-pip.py --force-reinstall

在驗證一下

pip3 -V
pip 10.0.1 from /usr/local/lib/python3.6/dist-packages/pip (python 3.6)

Ubuntu18.04 升級python3後 安裝pip3 後報錯