You can use python -V (et al.) to show you the version of Python that the python command resolves to. If that's all you need, you're done. But to see every version of python in your system takes a bit more.
In Ubuntu we can check the resolution with readlink -f $(which python). In default cases in 14.04 this will simply point to /usr/bin/python2.7.
We can chain this in to show the version of that version of Python:
$ readlink -f $(which python) | xargs -I % sh -c 'echo -n "%: "; % -V'
/usr/bin/python2.7: Python 2.7.6
But this is still only telling us what our current python resolution is. If we were in a Virtualenv (a common Python stack management system) python might resolve to a different version:
$ readlink -f $(which python) | xargs -I % sh -c 'echo -n "%: "; % -V'
/home/oli/venv/bin/python: Python 2.7.4
This is real output.
The fact is there could be hundreds of different versions of Python secreted around your system, either on paths that are contextually added, or living under different binary names (like python3).
If we assume that a Python binary is always going to be called python<something> and be a binary file, we can just search the entire system for files that match those criteria:
$ sudo find / -type f -executable -iname 'python*' -exec file -i '{}' \; | awk -F: '/x-executable; charset=binary/ {print $1}' | xargs readlink -f | sort -u | xargs -I % sh -c 'echo -n "%: "; % -V'
/home/oli/venv/bin/python: Python 2.7.4
/media/ned/websites/venvold/bin/python: Python 2.7.4
/srv/chroot/precise_i386/usr/bin/python2.7: Python 2.7.3
/srv/chroot/trusty_i386/usr/bin/python2.7: Python 2.7.6
/srv/chroot/trusty_i386/usr/bin/python3.4: Python 3.4.0
/srv/chroot/trusty_i386/usr/bin/python3.4m: Python 3.4.0
/usr/bin/python2.7: Python 2.7.6
/usr/bin/python2.7-dbg: Python 2.7.6
/usr/bin/python3.4: Python 3.4.0
/usr/bin/python3.4dm: Python 3.4.0
/usr/bin/python3.4m: Python 3.4.0
/web/venvold/bin/python: Python 2.7.4
It's obviously a pretty hideous command but this is again real output and it seems to have done a fairly thorough job.
Answer from Oli on askubuntu.comYou can use python -V (et al.) to show you the version of Python that the python command resolves to. If that's all you need, you're done. But to see every version of python in your system takes a bit more.
In Ubuntu we can check the resolution with readlink -f $(which python). In default cases in 14.04 this will simply point to /usr/bin/python2.7.
We can chain this in to show the version of that version of Python:
$ readlink -f $(which python) | xargs -I % sh -c 'echo -n "%: "; % -V'
/usr/bin/python2.7: Python 2.7.6
But this is still only telling us what our current python resolution is. If we were in a Virtualenv (a common Python stack management system) python might resolve to a different version:
$ readlink -f $(which python) | xargs -I % sh -c 'echo -n "%: "; % -V'
/home/oli/venv/bin/python: Python 2.7.4
This is real output.
The fact is there could be hundreds of different versions of Python secreted around your system, either on paths that are contextually added, or living under different binary names (like python3).
If we assume that a Python binary is always going to be called python<something> and be a binary file, we can just search the entire system for files that match those criteria:
$ sudo find / -type f -executable -iname 'python*' -exec file -i '{}' \; | awk -F: '/x-executable; charset=binary/ {print $1}' | xargs readlink -f | sort -u | xargs -I % sh -c 'echo -n "%: "; % -V'
/home/oli/venv/bin/python: Python 2.7.4
/media/ned/websites/venvold/bin/python: Python 2.7.4
/srv/chroot/precise_i386/usr/bin/python2.7: Python 2.7.3
/srv/chroot/trusty_i386/usr/bin/python2.7: Python 2.7.6
/srv/chroot/trusty_i386/usr/bin/python3.4: Python 3.4.0
/srv/chroot/trusty_i386/usr/bin/python3.4m: Python 3.4.0
/usr/bin/python2.7: Python 2.7.6
/usr/bin/python2.7-dbg: Python 2.7.6
/usr/bin/python3.4: Python 3.4.0
/usr/bin/python3.4dm: Python 3.4.0
/usr/bin/python3.4m: Python 3.4.0
/web/venvold/bin/python: Python 2.7.4
It's obviously a pretty hideous command but this is again real output and it seems to have done a fairly thorough job.
Type following in the terminal (Ctrl+Alt+T):
python -V
or
python --version
You can find a list of options/parameters for many commands in the terminal by typing the command followed by --help
Example:
python --help
Manual/manpages also available for most of such CLI which can be displayed by man <command> (Ex: man python)
From man python:
COMMAND LINE OPTIONS
-V , --version
Prints the Python version number of the executable and exits.
There is also python3 installed on many machines, so you can do:
python3 --version
to find out what python 3.x you are running.
Videos
Hey there, how can I update my Python version to its latest version? I have done
Sudo apt update and upgrade
But I am still on python version 3.8.10
What to do?
When you install from source, by default, the installation goes in /usr/local -- the executable in particular becomes /usr/local/bin/pythonX.Y with a symlink to it that's named /usr/local/python. Ubuntu's own installation is in /usr/ (e.g., /usr/bin/python), so the new installation won't overwrite it. Take care that the PATH environment variable doesn't have /usr/local/bin before /usr/bin, or else simple mentions of python would execute the new one, not the old one.
I'm just going to assume that by "newer version" you mean "released version that is newer than the default version in Ubuntu". That means python 3.1, which is in the repositories.
sudo apt-get install python3
Different python versions in the Ubuntu repositories can coexist with one another just fine. If you're on a version of Ubuntu older than Lucid, you'll have to upgrade your OS or enable the universe repository in order for python3 to show up in your package manager.
If you mean python 2.7, you should be aware that it hasn't been released yet.