Install Python of specific version system-wide with pyenv

Question

I am researching possibility to upgrade to Python 3.6 in our project.

Right now we are using Python 3.5.2 from ppa:fkrull/deadsnakes on Ubuntu 14.04. The PPA doesn't have Python 3.6 yet and it's not clear when it will be available.

I don't want to install yet another PPA.

And I am trying to find a more general approach.

I found people suggesting to use pyenv which compiles Python from source, which sounds interesting, because I can upgrade Python any time without waiting until repo maintainer adds it. Also I can easily install other Python flavors like PyPy.

I am not ready to use pyenv as virtual environment yes, so I am wondering if it's possible to use it to compile and install Python globally so that I can just use it.

Answer 1

The documentation is a little confusing because there is no python-build binary added in PATH after installation.

python-build is a pyenv plugin (installed by default). Documentation and more info is here: https://github.com/pyenv/pyenv/tree/master/plugins/python-build.

How to install system-wide Python for all users: 1) Login as root and 2) install required Python version to /usr/local/python-X.Y.Z.

sudo ~/.pyenv/plugins/python-build/bin/python-build 3.6.1 /usr/local/python-3.6.1/

Now you can use this Python version as a normal user, for example you can create virtualenv for your project:

/usr/local/python-3.6.1/bin/python -m venv /var/www/my-app/.env/

Answer 2

https://github.com/yyuu/pyenv/wiki/Common-build-problems#installing-a-system-wide-python

Installing a system-wide Python

If you want to install a Python interpreter that's available to all users and system scripts (no pyenv), use /usr/local/ as the install path. For example:

sudo python-build 3.3.2 /usr/local/

Answer 3

I've contributed a package for python3.6 in deadsnakes for trusty / xenial :)

https://launchpad.net/~fkrull/+archive/ubuntu/deadsnakes/+packages?field.name_filter=python3.6&field.status_filter=published&field.series_filter=

Answer 4

By combining the hints from the other answers and reading through the documentation, I found a nice way to do exactly what you want that should work well in a CI system or in a Docker container or on a developer machine if they haven't already installed python3.x via Apt or Yum or Homebrew.

Assuming you have all the dependencies required to build your desired version of Python 3.x (anything above 3.4 requires some extra packages the pyenv-installer doesn't always warn you about), you can run the commands below to get a new system wide Python that should be executable by all users, which makes it easy to pass to virtualenv creations with python3.6 -m venv yourvenv.

curl https://pyenv.run | bash # or
wget -O - https://pyenv.run | bash

export PATH="$HOME/.pyenv/bin:$PATH"
$(pyenv which python-build) 3.6.10 /usr/local/

which python3.6
python3.6 --version
# If you get an error running the above commands, it probably means
# /usr/local/bin isn't in your PATH yet
# on Debian/Ubuntu and maybe others the /etc/environment or 
# /etc/login.defs file puts it in the path when a user logs in
echo $PATH
export PATH="/usr/local/bin:$PATH"
python3.6 --version