pyenv Simple Python Version Management

[snippsat]

Here gone look at setting up pyenv.
Will be using for Mint 19,work same for Ubuntu 18,for other look at wiki.
Both of these distros come with Python 3.6.5 as default Python 3 so pretty good updated.
Will be using pyenv to install Python 3.7.2 first,later look at eg Anaconda,PyPy...ect.

tom@tom-VirtualBox:~$ python -V Python 2.7.15rc1 tom@tom-VirtualBox:~$ python3 -V Python 3.6.5

Why pyenv?

• pyenv will install Python or other Distribution(Anaconda,PyPy,MicroPython...ect),set it as system wide installation(or run it in a shell seesion).
  
• No more using python3 or pip3 or sudo or --user when pip install something.
  
• It's always python and pip to version set as global,eg pip install requests to global version.
  
• It's safe and will not mess with your OS,can go back to default pyenv local system or remove all rm -rf $(pyenv root)
  

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Setting up pyenv
This is a one time setup.

1. Install tool for building Python and distributions
   
2. Use git to download and install pyenv
   
3. Add 4 lines last in ~/.bashrc
   

1. Install building tools
Look at wiki for eg Mac OS X and other distros.

sudo apt-get update sudo apt-get install python3-dev sudo apt install python3-pip sudo apt-get install -y make build-essential libssl-dev zlib1g-dev libbz2-dev libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev xz-utils tk-dev libxml2-dev libxmlsec1-dev libffi-dev # Scientific package headers(Numpy, Matplotlib, SciPy, etc.) sudo apt-get install -y libpng-dev libfreetype6-dev

2. This download and install pyenv

git clone https://github.com/pyenv/pyenv.git ~/.pyenv git clone https://github.com/pyenv/pyenv-virtualenv.git $(pyenv root)/plugins/pyenv-virtuale git clone https://github.com/pyenv/pyenv-update.git $(pyenv root)/plugins/pyenv-update

3. Add to ~/.bashrc
Open in nano as shown under,or eg vim or text editor of choice.

nano ~/.bashrc

Add these 4 lines last in ~/.bashrc

# Load pyenv automatically when shell start export PATH="~/.pyenv/bin:$PATH" eval "$(pyenv init -)" eval "$(pyenv virtualenv-init -)"

Save:

Ctrl-O <enter>(save) Ctrl-X(exit)

Restart shell.

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pyenv test and usage
As see under no error loading using pyenv command.

tom@tom-VirtualBox:~$ pyenv version 3.7.2 (set by /home/tom/.pyenv/version) tom@tom-VirtualBox:~$ python -V Python 3.7.2

Now can look at pyenv install --list

Hide/Show

Output:
tom@tom-VirtualBox:~$ pyenv install --list Available versions: 2.1.3 2.2.3 2.3.7 2.4 2.4.1 2.4.2 2.4.3 2.4.4 2.4.5 2.4.6 2.5 2.5.1 2.5.2 2.5.3 2.5.4 2.5.5 2.5.6 2.6.6 2.6.7 2.6.8 2.6.9 2.7-dev 2.7 2.7.1 2.7.2 2.7.3 2.7.4 2.7.5 2.7.6 2.7.7 2.7.8 2.7.9 2.7.10 2.7.11 2.7.12 2.7.13 2.7.14 2.7.15 3.0.1 3.1 3.1.1 3.1.2 3.1.3 3.1.4 3.1.5 3.2 3.2.1 3.2.2 3.2.3 3.2.4 3.2.5 3.2.6 3.3.0 3.3.1 3.3.2 3.3.3 3.3.4 3.3.5 3.3.6 3.3.7 3.4.0 3.4-dev 3.4.1 3.4.2 3.4.3 3.4.4 3.4.5 3.4.6 3.4.7 3.4.8 3.4.9 3.5.0 3.5-dev 3.5.1 3.5.2 3.5.3 3.5.4 3.5.5 3.5.6 3.6.0 3.6-dev 3.6.1 3.6.2 3.6.3 3.6.4 3.6.5 3.6.6 3.6.7 3.6.8 3.7.0 3.7-dev 3.7.1 3.7.2 3.8-dev activepython-2.7.14 activepython-3.5.4 activepython-3.6.0 anaconda-1.4.0 anaconda-1.5.0 anaconda-1.5.1 anaconda-1.6.0 anaconda-1.6.1 anaconda-1.7.0 anaconda-1.8.0 anaconda-1.9.0 anaconda-1.9.1 anaconda-1.9.2 anaconda-2.0.0 anaconda-2.0.1 anaconda-2.1.0 anaconda-2.2.0 anaconda-2.3.0 anaconda-2.4.0 anaconda-4.0.0 anaconda2-2.4.0 anaconda2-2.4.1 anaconda2-2.5.0 anaconda2-4.0.0 anaconda2-4.1.0 anaconda2-4.1.1 anaconda2-4.2.0 anaconda2-4.3.0 anaconda2-4.3.1 anaconda2-4.4.0 anaconda2-5.0.0 anaconda2-5.0.1 anaconda2-5.1.0 anaconda2-5.2.0 anaconda2-5.3.0 anaconda2-5.3.1 anaconda2-2018.12 anaconda3-2.0.0 anaconda3-2.0.1 anaconda3-2.1.0 anaconda3-2.2.0 anaconda3-2.3.0 anaconda3-2.4.0 anaconda3-2.4.1 anaconda3-2.5.0 anaconda3-4.0.0 anaconda3-4.1.0 anaconda3-4.1.1 anaconda3-4.2.0 anaconda3-4.3.0 anaconda3-4.3.1 anaconda3-4.4.0 anaconda3-5.0.0 anaconda3-5.0.1 anaconda3-5.1.0 anaconda3-5.2.0 anaconda3-5.3.0 anaconda3-5.3.1 anaconda3-2018.12 ironpython-dev ironpython-2.7.4 ironpython-2.7.5 ironpython-2.7.6.3 ironpython-2.7.7 jython-dev jython-2.5.0 jython-2.5-dev jython-2.5.1 jython-2.5.2 jython-2.5.3 jython-2.5.4-rc1 jython-2.7.0 jython-2.7.1 micropython-dev micropython-1.9.3 micropython-1.9.4 miniconda-latest miniconda-2.2.2 miniconda-3.0.0 miniconda-3.0.4 miniconda-3.0.5 miniconda-3.3.0 miniconda-3.4.2 miniconda-3.7.0 miniconda-3.8.3 miniconda-3.9.1 miniconda-3.10.1 miniconda-3.16.0 miniconda-3.18.3 miniconda2-latest miniconda2-3.18.3 miniconda2-3.19.0 miniconda2-4.0.5 miniconda2-4.1.11 miniconda2-4.3.14 miniconda2-4.3.21 miniconda2-4.3.27 miniconda2-4.3.30 miniconda3-latest miniconda3-2.2.2 miniconda3-3.0.0 miniconda3-3.0.4 miniconda3-3.0.5 miniconda3-3.3.0 miniconda3-3.4.2 miniconda3-3.7.0 miniconda3-3.8.3 miniconda3-3.9.1 miniconda3-3.10.1 miniconda3-3.16.0 miniconda3-3.18.3 miniconda3-3.19.0 miniconda3-4.0.5 miniconda3-4.1.11 miniconda3-4.2.12 miniconda3-4.3.11 miniconda3-4.3.14 miniconda3-4.3.21 miniconda3-4.3.27 miniconda3-4.3.30 pypy-c-jit-latest pypy-c-nojit-latest pypy-dev pypy-stm-2.3 pypy-stm-2.5.1 pypy-1.5-src pypy-1.5 pypy-1.6 pypy-1.7 pypy-1.8 pypy-1.9 pypy-2.0-src pypy-2.0 pypy-2.0.1-src pypy-2.0.1 pypy-2.0.2-src pypy-2.0.2 pypy-2.1-src pypy-2.1 pypy-2.2-src pypy-2.2 pypy-2.2.1-src pypy-2.2.1 pypy-2.3-src pypy-2.3 pypy-2.3.1-src pypy-2.3.1 pypy-2.4.0-src pypy-2.4.0 pypy-2.5.0-src pypy-2.5.0 pypy-2.5.1-src pypy-2.5.1 pypy-2.6.0-src pypy-2.6.0 pypy-2.6.1-src pypy-2.6.1 pypy-4.0.0-src pypy-4.0.0 pypy-4.0.1-src pypy-4.0.1 pypy-5.0.0-src pypy-5.0.0 pypy-5.0.1-src pypy-5.0.1 pypy-5.1-src pypy-5.1 pypy-5.1.1-src pypy-5.1.1 pypy-5.3-src pypy-5.3 pypy-5.3.1-src pypy-5.3.1 pypy-5.4-src pypy-5.4 pypy-5.4.1-src pypy-5.4.1 pypy-5.6.0-src pypy-5.6.0 pypy-5.7.0-src pypy-5.7.0 pypy-5.7.1-src pypy-5.7.1 pypy2-5.3-src pypy2-5.3 pypy2-5.3.1-src pypy2-5.3.1 pypy2-5.4-src pypy2-5.4 pypy2-5.4.1-src pypy2-5.4.1 pypy2-5.6.0-src pypy2-5.6.0 pypy2-5.7.0-src pypy2-5.7.0 pypy2-5.7.1-src pypy2-5.7.1 pypy2.7-5.8.0-src pypy2.7-5.8.0 pypy2.7-5.9.0-src pypy2.7-5.9.0 pypy2.7-5.10.0-src pypy2.7-5.10.0 pypy2.7-6.0.0-src pypy2.7-6.0.0 pypy3-dev pypy3-2.3.1-src pypy3-2.3.1 pypy3-2.4.0-src pypy3-2.4.0 pypy3.3-5.2-alpha1-src pypy3.3-5.2-alpha1 pypy3.3-5.5-alpha-src pypy3.3-5.5-alpha pypy3.5-c-jit-latest pypy3.5-5.7-beta-src pypy3.5-5.7-beta pypy3.5-5.7.1-beta-src pypy3.5-5.7.1-beta pypy3.5-5.8.0-src pypy3.5-5.8.0 pypy3.5-5.9.0-src pypy3.5-5.9.0 pypy3.5-5.10.0-src pypy3.5-5.10.0 pypy3.5-5.10.1-src pypy3.5-5.10.1 pypy3.5-6.0.0-src pypy3.5-6.0.0 pyston-0.5.1 pyston-0.6.0 pyston-0.6.1 stackless-dev stackless-2.7-dev stackless-2.7.2 stackless-2.7.3 stackless-2.7.4 stackless-2.7.5 stackless-2.7.6 stackless-2.7.7 stackless-2.7.8 stackless-2.7.9 stackless-2.7.10 stackless-2.7.11 stackless-2.7.12 stackless-2.7.14 stackless-3.2.2 stackless-3.2.5 stackless-3.3.5 stackless-3.3.7 stackless-3.4-dev stackless-3.4.1 stackless-3.4.2 stackless-3.4.7 stackless-3.5.4

A lot to choice from,let's go back in time and install Python 2.4 and set it Global(system wide installation).

tom@tom-VirtualBox:~$ pyenv install 2.4 Downloading Python-2.4.tgz... -> https://www.python.org/ftp/python/2.4/Python-2.4.tgz Installing Python-2.4... Installed setuptools-1.4.2 to /home/tom/.pyenv/versions/2.4 Installed pip-1.1 to /home/tom/.pyenv/versions/2.4 tom@tom-VirtualBox:~$ pyenv global 2.4 tom@tom-VirtualBox:~$ python -V Python 2.4 tom@tom-VirtualBox:~$ pip -V usage: pip COMMAND [OPTIONS] pip: error: no such option: -V

As we see back to pip version 1.1(newest today is 18.1),it did not even have -V to show version.
But it's installed.

tom@tom-VirtualBox:~$ pip usage: pip COMMAND [OPTIONS] pip: error: You must give a command (use "pip help" to see a list of commands)

Let's go back to Python 3.7.2,flexibility is the strength of pyenv.

tom@tom-VirtualBox:~$ pyenv global 3.7.2 tom@tom-VirtualBox:~$ python -V Python 3.7.2 tom@tom-VirtualBox:~$ pip -V pip 18.1 from /home/tom/.pyenv/versions/3.7.2/lib/python3.7/site-packages/pip (python 3.7)

[snippsat]

Upgrade to Python 3.8.1 this should be easy if have pyenv up and working.
Here is demo on my Linux Mint 19.

# Update pyenv to get new versions list tom@tom:~$ pyenv update # Look at available versions tom@tom:~$ pyenv install --list ..... 3.7.5 3.7.5rc1 3.7.6 3.8.0 3.8-dev 3.8.1 3.9-dev # Install tom@tom:~$ 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/tom/.pyenv/versions/3.8.1 # Set as system wide version tom@tom:~$ pyenv global 3.8.1 # Test tom@tom:~$ python Python 3.8.1 (default, Feb 11 2020, 09:18:58) [GCC 7.3.0] on linux Type "help", "copyright", "credits" or "license" for more information. >>> print(walrus := True) True >>> exit() tom@tom:~$ pip -V pip 19.2.3 from /home/tom/.pyenv/versions/3.8.1/lib/python3.8/site-packages/pip (python 3.8)