How to switch Python versions in Terminal?
Question:
My Mac came with Python 2.7 installed by default, but I’d like to use Python 3.6.1 instead.
How can I change the Python version used in Terminal (on Mac OS)?
Please explain clearly and offer no third party version manager suggestions.
Answers:
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
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.
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.
You can just specify the python version when running a program:
for python 2:
python filename.py
for python 3:
python3 filename.py
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.
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.
Usage
$ 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 on a MacBook.
- Open the terminal.
- Type nano ~/.bash_profile and enter. (Or vim instead of nano if you use vim.)
- Now add the line alias python=python3
- Press CTRL + x then y to save it. (Or just save it on vim since you can’t exit vim.)
- It will prompt for the file name, simply hit enter.
- Now check the python version by using the command: python –version
- If you see 2.0.0+, it worked!
I am a beginner in python and was looking for the same and in the terminal, I just typed python3 and it came up with the newest version. I am thinking that if one wants to go to a different version they can just type that in? Could be wrong but this is what shows up when I typed python3.
% python3
Python 3.9.2 (v3.9.2:1a79785e3e, Feb 19 2021, 09:06:10)
[Clang 6.0 (clang-600.0.57)] on darwin
Before when I just typed python. This is the message I would get.
% python2.7
WARNING: Python 2.7 is not recommended.
This version is included in macOS for compatibility with legacy software.
Future versions of macOS will not include Python 2.7.
Instead, it is recommended that you transition to using 'python3' from within Terminal.
Python 2.7.16 (default, Jun 5 2020, 22:59:21)
[GCC 4.2.1 Compatible Apple LLVM 11.0.3 (clang-1103.0.29.20) (-macos10.15-objc- on darwin
Type "help", "copyright", "credits" or "license" for more information.
You can open and use zsh terminal on Mac OS.
Edit file /Users/{your_username}/.zshrc using nano or vim.
Add new alias for python 3
alias python="python3"
Save and check your python version using this following command.
python --version
Look at the result:
In order to easily manage the different python versions. Please use below link to see how to use the versions effectively and without any environment variables.
https://youtu.be/jTN4MHNhJZs
ON WINDOWS HOWEVER…
sometimes you could just rename the file to "python3" in a python 3 enviroment
the program itself will still work but some ides will break for obvious reasons…
so my answer works on windows but it makes ides that dont have support for enviroments break
why am i the only windows user to mention this
My Mac came with Python 2.7 installed by default, but I’d like to use Python 3.6.1 instead.
How can I change the Python version used in Terminal (on Mac OS)?
Please explain clearly and offer no third party version manager suggestions.
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
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.
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.
You can just specify the python version when running a program:
for python 2:
python filename.py
for python 3:
python3 filename.py
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.
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.
Usage
$ 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 on a MacBook.
- Open the terminal.
- Type nano ~/.bash_profile and enter. (Or vim instead of nano if you use vim.)
- Now add the line alias python=python3
- Press CTRL + x then y to save it. (Or just save it on vim since you can’t exit vim.)
- It will prompt for the file name, simply hit enter.
- Now check the python version by using the command: python –version
- If you see 2.0.0+, it worked!
I am a beginner in python and was looking for the same and in the terminal, I just typed python3 and it came up with the newest version. I am thinking that if one wants to go to a different version they can just type that in? Could be wrong but this is what shows up when I typed python3.
% python3
Python 3.9.2 (v3.9.2:1a79785e3e, Feb 19 2021, 09:06:10)
[Clang 6.0 (clang-600.0.57)] on darwin
Before when I just typed python. This is the message I would get.
% python2.7
WARNING: Python 2.7 is not recommended.
This version is included in macOS for compatibility with legacy software.
Future versions of macOS will not include Python 2.7.
Instead, it is recommended that you transition to using 'python3' from within Terminal.
Python 2.7.16 (default, Jun 5 2020, 22:59:21)
[GCC 4.2.1 Compatible Apple LLVM 11.0.3 (clang-1103.0.29.20) (-macos10.15-objc- on darwin
Type "help", "copyright", "credits" or "license" for more information.
You can open and use zsh terminal on Mac OS.
Edit file /Users/{your_username}/.zshrc using nano or vim.
Add new alias for python 3
alias python="python3"
Save and check your python version using this following command.
python --version
Look at the result:
In order to easily manage the different python versions. Please use below link to see how to use the versions effectively and without any environment variables.
https://youtu.be/jTN4MHNhJZs
ON WINDOWS HOWEVER…
sometimes you could just rename the file to "python3" in a python 3 enviroment
the program itself will still work but some ides will break for obvious reasons…
so my answer works on windows but it makes ides that dont have support for enviroments break
why am i the only windows user to mention this