How can I upgrade my current python3 version from 3.6.9 to 3.8? I don't want to setup python 3.8 as a separate version. Because I don't want to type python3.8 command rather than python3 every time.
Don't do that, 3.6 is default Python 3 in Bionic.
If you just want less typing then define shell alias.
pyenvfor a solution to set up Python 3.8 in userspace and to designate what version to use locally in your shell for the
python3call when using the Terminal and such, rather than using the system Python. This will also protect you from breaking your system's Python shell. github.com/pyenv/pyenv