Kali Linux – How to upgrade python 2.7 to python 3.7
I have covered changing the default version of python in Debian, however for those looking to Google for a quick fix on Kali, I hope that this reaches you well.
This was tested on a completely fresh install of Kali Linux with no other alterations made prior.
The basic premise is to configure Kali to use python 3.7 at a higher priority to python 2.7 or any other version installed on the system.
Check your python version
Step 1 is to check your current python version:
python -V
or
python --version
Kali default output:
Python 2.7.17
Set your Python Default
Now it is time configure the priority for the versions of python that we have installed, 2.7 and 3.5/7. You can list all of the available alternatives installed by running:
ls /usr/bin/python*
To set your version priorities, with 3.7 being the high priority:
update-alternatives --install /usr/bin/python python /usr/bin/python2.7 1
update-alternatives --install /usr/bin/python python /usr/bin/python3.7 2
We have just set 3.7 (2) to have a priority great than 2.7 (1). Now when we list the python priorities we see see 3.7 is higher that 2.7:
update-alternatives --config python

This is also a great way to easily switch those priorities around once they have been set.
Check you default version, again…
python -V
Now this command should return the default which you configured above.

Other Useful Python tips:
- https://exitcode0.net/debian-9-how-to-upgrade-python-3-5-to-python-3-7/ – Debian 9 – How to upgrade python 3.5 to python 3.7
- https://exitcode0.net/changing-the-default-python-version-in-debian/ – Changing the default python version in Debian
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Thank you very much Bro, you helped me out. Was stuck on this from so long.
I still see the following:
(base) root@kali:~/Desktop/For_lab10# update-alternatives –config python
There are 2 choices for the alternative python (providing /usr/bin/python).
Selection Path Priority Status
————————————————————
* 0 /usr/bin/python3.6 2 auto mode
1 /usr/bin/python2.7 1 manual mode
2 /usr/bin/python3.6 2 manual mode
Press to keep the current choice[*], or type selection number:
(base) root@kali:~/Desktop/For_lab10# python -V
Python 2.7.16 :: Anaconda, Inc.