The simplest way would be to add an alias to python3
to always point to the native python
installed. Add this line to the .bash_profile
file in your $HOME
directory at the last,
alias python="python3"
Doing so makes the changes to be reflected on every interactive shell opened.
You can just specify the python version when running a program:
for python 2:
python filename.py
for python 3:
python3 filename.py
pyenv
is a 3rd party version manager which is super commonly used (18k stars, 1.6k forks) and exactly what I looked for when I came to this question.
Install pyenv
.
$ pyenv install --list
Available versions:
2.1.3
[...]
3.8.1
3.9-dev
activepython-2.7.14
activepython-3.5.4
activepython-3.6.0
anaconda-1.4.0
[... a lot more; including anaconda, miniconda, activepython, ironpython, pypy, stackless, ....]
$ pyenv install 3.8.1
Downloading Python-3.8.1.tar.xz...
-> https://www.python.org/ftp/python/3.8.1/Python-3.8.1.tar.xz
Installing Python-3.8.1...
Installed Python-3.8.1 to /home/moose/.pyenv/versions/3.8.1
$ pyenv versions
* system (set by /home/moose/.pyenv/version)
2.7.16
3.5.7
3.6.9
3.7.4
3.8-dev
$ python --version
Python 2.7.17
$ pip --version
pip 19.3.1 from /home/moose/.local/lib/python3.6/site-packages/pip (python 3.6)
$ mkdir pyenv-experiment && echo "3.8.1" > "pyenv-experiment/.python-version"
$ cd pyenv-experiment
$ python --version
Python 3.8.1
$ pip --version
pip 19.2.3 from /home/moose/.pyenv/versions/3.8.1/lib/python3.8/site-packages/pip (python 3.8)
I have followed the below steps in Macbook.
Here is a nice and simple way to do it (but on CENTOS), without braking the operating system.
yum install scl-utils
next
yum install centos-release-scl-rh
And lastly you install the version that you want, lets say python3.5
yum install rh-python35
And lastly:
scl enable rh-python35 bash
Since MAC-OS is a unix operating system, the way to do it it should be quite similar.
As Inian suggested, you should alias python to point to python 3. It is very easy to do, and very easy to switchback, personally i have an alias setup for p2=python2 and p3=python3 as well to save on keystrokes. Read here for more information: How do I create a Bash alias?
Here is an example of doing so for python:
alias python=python3
Like so:
$ python --version
Python 2.7.6
$ python3 --version
Python 3.4.3
$ alias python=python3
$ python --version
Python 3.4.3
See here for the original: https://askubuntu.com/questions/320996/how-to-make-python-program-command-execute-python-3
If you have python various versions of python installed,you can launch any of them using pythonx.x.x
where x.x.x
represents your versions.
Source: Stackoverflow.com