How to remove default Python, install latest version on Raspbian

Question

I just got my first Raspberry Pi, and I wanted to use the latest version of Python, but I don't know how to set it up so that when I run python in the command line, it will run Python 3.8.2, rather than 3.7.3. I downloaded the latest release of Python from the website, but it's not a setup script, and I'm not sure how to set it to the path otherwise. Is there a way to replace the default version on Raspbian with the version I've just downloaded?

This is my first time working with any kind of Linux distro, so when I look for the answer on SO or elsewhere, I don't quite know how to word it, and there are very different answers, which makes me think I'm not asking the right question. What could I be doing wrong, and how can I set it up correctly?

Thanks.

Answer 1

First Way: You can change Python 3.8.x as the default to Python 3.8.x.

As you said that you have already installed the latest version.Right after that,
Add Python3.8.x & Python 3.8.x to update-alternatives

sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.8.0 1
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.8.2 2

Update Python 3 to point to Python 3.8.x

sudo update-alternatives --config python3 Enter 2 for Python 3.8.2 or 1 for 3.8.0

python3 --version
Python 3.8.2 

Second Way: Find out what python binary executables are available on your system.

$ ls /usr/bin/python*
/usr/bin/python3.8.0  /usr/bin/python3.8.2 

To Change python version:
Create an alias within user's home directory. Open ~/.bashrc file and add new alias to change your default python executable:

alias python='/usr/bin/python3.8.2'

Once you make the above change, re-login or source your .bashrc file:

$ . ~/.bashrc

Check your default python version:

   $ python --version
    Python 3.8.2