pip 安裝包時報錯 /usr/bin/pip: No such file or directory

在ubuntu中使用pip報一下錯誤:
/usr/bin/pip: No such file or directory pip can no longer be found: 可以採用以下方式解決

which pip
/usr/local/bin/pip

pip
-su: /usr/bin/pip: No such file or directory

type pip
pip is hashed (/usr/bin/pip)
So pip is definintely in /usr/local/bin/pip but it is been cached as in /usr/bin/pip, thanks to the Stackoverflow question, the solution is very simple: hash -r
When the cache is clear, pip is working again.

這樣之後在進行操作，就可以使用pip了。