Compile Python

This is a small bash script to compile one or multiple Python versions.

I use it on my laptop, using Debian, but it may work on other distribs.

On Debian (and Debian-based distribs) it needs the following dependencies:

apt install make build-essential libssl-dev zlib1g-dev libbz2-dev \
libreadline-dev libsqlite3-dev wget curl llvm libncursesw5-dev \
xz-utils tk-dev libxml2-dev libxmlsec1-dev libffi-dev liblzma-dev

Installation

Clone the repo anywhere, then in your ~/.bashrc add:

source PATH/To/THE/REPO/compile-python.sh

And for the compiled Python to be found in your PATH:

PATH="$PATH:$HOME/.local/bin"

Usage

$ compile-pythons
$ python3.6 --version
Python 3.6.15
$ python3.7 --version
Python 3.7.12
$ python3.8 --version
Python 3.8.12
$ python3.9 --version
Python 3.9.9
$ python3.10 --version
Python 3.10.1
$ python3.11 --version
Python 3.11.0a2

How it works

It downloads official Python sources (from https://www.python.org/ftp/python/), then compiles them using --with-pydebug (it's a dev tool, don't use it in production! Rely on your distrib in production!), and --prefix=~/.local, and finally installs it using make altinstall.

Anyway it's ~67 lines of code, maybe just read it.

Be nice with distrib' provided Python

compile-python only produces binaries on the form pythonX.Y (like python3.8), so python3 and python will always point to your distrib' Python.

But beware, depending on how you setup your PATH, pythonY.X may point to your distrib' Python, or to your manually compiled one.

On Debian, don't hesitate to apt install python-is-python3 if you want python to be python3.

Functions

The file declares 3 functions:

• compile-pythons: To compile a set of usefull Python versions.
• compile-python: To compile a given Python version (has autocompletion).
• venv: Just a wrapper to python -m venv that I like to use daily.

Using a function don't force you to use the others, they are not related.

compile-pythons

This is probably the one you're seeking, it compiles a bunch of usefull Python verisons, typically usefull if you use tox and need multiple Python versions to test your project.

compile-python

This one is used by compile-python but you can use it manually, like:

compile-python 3.10.1

venv

A bit unrelated to the two others, here for historical reasons, this is how I create venvs. I use it like:

$ venv

If the venv does not exists it's created, if it exist it's just activated.

It takes an optional parameter: the Python version to use, like venv 3.10 or venv 3.6.

The venv prompt takes the name of the current directory plus the version, like:

(compile-python)(py3.10.0) mdk@seaph:~/ $

which I find usefull, but feel free to not use it.

Why not using pyenv?

I know pyenv exists, I even used it back in the time. I did not appreciated the shims part (I'm not saying it's bad), so I tried myself as something more simple: just build Python and that's it.