How to uninstall python 2.17.13, and keep python 3.7.6 as the default version on debian 9?

I installed a Django package on GCP (Debian 9 OS), that comes with the following softwares:

Django (2.2.9)
Git (2.25.0)
Apache (2.4.41)
lego (3.3.0)
MySQL (5.7.29)
Node.js (10.18.1)
OpenSSL (1.1.1d)
PostgreSQL (11.6)
Python (3.7.6)
SQLite (3.31.0.)
Subversion (1.13.0)

When I type the command python -V

I get the following python version: 2.17.13

When I type python3 -V

I get the following version: 3.7.6

How can I uninstall the previous version permanently and keep the current one as the default?

Here's what I tried and I didn't work:

$ ls /usr/bin/python*

usr/bin/python /usr/bin/python2.7 /usr/bin/python3.5 /usr/bin/python3m /usr/bin/python2 /usr/bin/python3 /usr/bin/python3.5m

# update-alternatives --install /usr/bin/python python /usr/bin/python2.7 1

Returns nothing

# update-alternatives --install /usr/bin/python python /usr/bin/python3.5 2

Returns nothing

Solution

I would not recommend uninstalling python2. Install python3 and make sure the directory where you install it is included in your systems $PATH variable. You will need to do something like this. Note, depending on how you install python3, some installers will automatically update your $PATH variable.

Example installing python3 in "/Library/Frameworks/python3" directory.

Show current $PATH variable.

echo $PATH

update .bashrc in home directory (append to current $PATH)

PATH="/Library/Frameworks/python3:${PATH}"

reload .bashrc (or exit and start terminal back up)

. ~/.bashrc

Confirm correct python install will be run when typing python3 into terminal.

$which python3
/Library/Frameworks/python3