How to update Python 3.5.3 to latest version?

Question

Python

Hello. There was a need to run one application written in Python
. As it turned out, an old version of Python itself was installed.

ls -la /usr/bin/python*
lrwxrwxrwx 1 root root       9 янв 24  2017 /usr/bin/python -> python2.7
lrwxrwxrwx 1 root root       9 янв 24  2017 /usr/bin/python2 -> python2.7
-rwxr-xr-x 1 root root 3795896 авг 22 13:03 /usr/bin/python2.7
lrwxrwxrwx 1 root root      33 авг 22 13:03 /usr/bin/python2.7-config -> x86_64-linux-gnu-python2.7-config
lrwxrwxrwx 1 root root      16 янв 24  2017 /usr/bin/python2-config -> python2.7-config
lrwxrwxrwx 1 root root       9 янв 20  2017 /usr/bin/python3 -> python3.5
-rwxr-xr-x 2 root root 4755312 ноя 19 00:09 /usr/bin/python3.5
-rwxr-xr-x 2 root root 4755312 ноя 19 00:09 /usr/bin/python3.5m
lrwxrwxrwx 1 root root      10 янв 20  2017 /usr/bin/python3m -> python3.5m
lrwxrwxrwx 1 root root      16 янв 24  2017 /usr/bin/python-config -> python2.7-config

I've looked all over the internet, but I haven't found anything clear.
I tried to compile from source, but this is apparently not enough for my application

python3.8 --version
Python 3.8.2

python3 --version
Python 3.5.3

python --version
Python 2.7.13

Answer 1

Well, you have Python 3.8.2, so run your application with this particular version.

Answer 2

Is this the latest version of python in debian turnips?
If so, find a third party turnip with fresh python and add it to the system.
If not - update debian itself
sudo apt update & sudo apt upgrade

Answer 3

pyenvmust be used.