I have limited space on my server, and I am thinking to delete the cache of the PIP. I am not sure if its safe to delete or not.
ls ~/.cache/pip/
Since pip 20.1b1, which was released on 21 April 2020 and "added pip cache command for inspecting/managing pip’s wheel cache", you no longer need to. Instead, you can issue this command:
pip cache purge
The reference guide is here:
https://pip.pypa.io/en/stable/reference/pip_cache/
The corresponding pull request is here.