get-pip.py を使って pip3 をインストールする
$ python3 get-pip.py
Defaulting to user installation because normal site-packages is not writeable
Collecting pip
Downloading pip-20.0.2-py2.py3-none-any.whl (1.4 MB)
|████████████████████████████████| 1.4 MB 3.1 MB/s
Collecting setuptools
Downloading setuptools-46.0.0-py3-none-any.whl (582 kB)
|████████████████████████████████| 582 kB 5.5 MB/s
Collecting wheel
Downloading wheel-0.34.2-py2.py3-none-any.whl (26 kB)
Installing collected packages: pip, setuptools, wheel
WARNING: The scripts pip, pip3 and pip3.5 are installed in '/home/yourname/.local/bin' which is not on PATH.
Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
WARNING: The scripts easy_install and easy_install-3.5 are installed in '/home/yourname/.local/bin' which is not on PATH.
Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
WARNING: The script wheel is installed in '/home/yourname/.local/bin' which is not on PATH.
Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
Successfully installed pip-20.0.2 setuptools-46.0.0 wheel-0.34.2