Python

From What is Python?:

Python is an interpreted, interactive, object-oriented programming language. It incorporates modules, exceptions, dynamic typing, very high level dynamic data types, and classes. It supports multiple programming paradigms beyond object-oriented programming, such as procedural and functional programming. Python combines remarkable power with very clear syntax. It has interfaces to many system calls and libraries, as well as to various window systems, and is extensible in C or C++. It is also usable as an extension language for applications that need a programmable interface. Finally, Python is portable: it runs on many Unix variants including Linux and macOS, and on Windows.

Installation

Install the python package, which provides the current release of Python 3.

Other versions

Previous and future versions of Python are available via the AUR, and may be useful for old applications that do not run on the current version, for programs intended to run on other versions, or just for curiosity:

Python 3.11: python311^AUR
Python 3.10: Current release, see previous section
Python 3.9:
Python 3.8:
Python 3.7:
Python 3.6: (unmaintained)
Python 2.7: (unmaintained)

Each of these packages installs a distinct binary named after the version number, e.g. python3.7 for Python 3.7, allowing multiple versions to coexist on a system. You can also use pyenv to easily switch between multiple versions of Python.

Extra modules/libraries for old versions of Python may be found on the AUR by searching for python<version without period>, e.g. searching for for Python 3.7 modules.

You can also download the source for any release on the https://www.python.org/downloads/ page.

Alternative implementations

The python package installs CPython, the reference implementation of Python. However, there are also other implementations available. These implementations are usually based on older versions of Python and are not fully compatible with CPython.

Implementations available on Arch Linux include:

More implementations exist. Some, such as Stackless, Pyston and Cinder are used internally at large technology companies. Others are historically notable but are no longer maintained due to improvements in the most popular implementations.

Alternative shells

The python package includes an interactive Python shell/REPL which can be launched with the command. The following shells are also available:

ptpython — An advanced Python REPL built with prompt-toolkit.

https://github.com/prompt-toolkit/ptpython || ptpython^AUR

Package management

There are several ways to install Python packages on Arch Linux:

Official repositories and AUR — A large number of popular packages are available in the Arch repositories. This is the preferred way to install system-wide packages.
pip(1) — The official package installer for Python. You can use pip to install packages from the Python Package Index and other indexes.

https://pip.pypa.io/ || python-pip

When installing packages using pip, it is recommended to use a virtual environment to prevent conflicts with system packages in . Alternatively, can be used to install packages into the user scheme instead of . pipx and Conda integrate environment management into their workflows.

See the Python Packaging User Guide for the official best practices for package management.

Historically, easy_install (part of ) was used to install packages distributed as Eggs. easy_install and Eggs have been replaced with pip and Wheels. See pip vs easy_install and Wheel vs Egg for more information.

Widget bindings

The following widget toolkit bindings are available:

Qt for Python (PySide2) — The official Python bindings for Qt5.

https://www.qt.io/qt-for-python || pyside2, pyside2-tools

pyQt — A set of Python bindings for Qt.

https://riverbankcomputing.com/software/pyqt/intro || python-pyqt5

To use these with Python, you may also need to install the associated widget toolkit packages (e.g. must also be installed to use Tkinter).

Tips and tricks

Virtual environment

Python provides tools to create isolated virtual environments into which packages may be installed without conflicting with other virtual environments or the system packages. Virtual environments can also run applications with different versions of Python on the same system.

See Python/Virtual environment for details.

Tab completion in Python shell

Tab completion is available in the interactive shell by default. Note that the readline completer will only complete names in the global namespace. You can use for a richer tab completion experience .

gollark: That sounds more like physics.

gollark: I'd say the axioms are invented/defined, but the consequences of those are discovered.

gollark: Alternatively, [0-9A-Za].

gollark: They're all called Bob. Done.

gollark: But can you prove it?