[Tutor] python -m pip install vs pip install

[Mats Wichmann]

On 09/10/2018 09:10 AM, Alex Kleider wrote:
> In another currently active thread Mats Wichmann recommends using:
>   python -m pip install ...
> vs
>   pip install ...
> 
> The question is how to install a specific version of python itself.
> 
> I'm running Ubuntu 16.04 and have the following notes to myself as to
> how to install version 3.6 which was the one I wanted at the time:
> 
>   sudo add-apt-repository ppa:jonathonf/python-3.6
>   sudo apt-get update
>   sudo apt-get install python3.6
>   pip install --user virtualenvwrapper
>   echo "source virtualenvwrapper.sh" >> ~/.bashrc
>   source ~/.bashrc
>   mkvirtualenv --python=python3.6 p36
> 
> Should I modify these notes?
> What should I do if/when I'm looking to use the next version (3.7 and
> beyond?)
> Will things be completely different if/when I finally decide to move up
> to Ubuntu 18.04?
> 
> Thanks,
> Alex
> 

I have done it this way, assuming I don't want to replace the system
Python. This is a completely optional framework, but I've found it useful.

One time only:
$ git clone https://github.com/pyenv/pyenv.git ~/.pyenv
# set up environment variables for use by pyenv,
# as noted in pyenv readme:
$ echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bash_profile
$ echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bash_profile

Any time I want to install a Python version:
$ pyenv rehash
$ pyenv install 3.7.0

Inside a project that wants to use 3.7.0:
$ pyenv local 3.7.0

To see what is available to install:
$ pyenv install list

To simplify creating virtualenvs, there is a pyenv-virtualenv plugin
described here:
https://github.com/pyenv/pyenv-virtualenv