*******************************************************************************
                                Install Python
*******************************************************************************

The `Python wiki <https://wiki.python.org/moin/BeginnersGuide/Download>`_
briefly describes the installation process.

.. note:: To become a **true** professional, you need a special software called
          :abbr:`IDE (Integrated Development Environment)` or at least a code
          editor supporting syntax highlight. Refer :doc:`/appx/code_edit` for
          more information.

Linux
=====

On most Linux distros Python comes pre-installed and/or all distro have it
available in their package repository (I haven't seen the one which does have).
The installation process depends on the distro, but here are some examples how
you can install it:

.. code-block::
    :caption: Install Python

    # Debian / Ubuntu (and other distros that uses ``apt``)
    apt install python3 python3-dev

    # ArchLinux
    pacman -S python3

    # RedHat, CentOS, Fedora
    dnf install python3 python3-devel

    # Gentoo
    # ... you should know what to do

MacOS
=====

For newer versions of MacOS Python is no longer included by default and you
will have to download and install it.

The process is described at: `Using Python on a Mac`_.

Briefly, you are invited to visit `downloads`_ and download the latest
stable version of Python. A "universal binary" build of Python runs natively on
Mac's new Intel and legacy PPC CPUs.

After the installation you would get:

- `Python 3.x` folder in `Applications` folder.
  Standard development environment (`IDLE`) and `PythonLauncher` included.
- A framework `/Library/Frameworks/Python.framework` included libraries and
  executables.

Install from Homebrew
---------------------

Python for MacOS is available via Homebrew. You are to search `formulae`_ for
the latest available version. In general, it's as easy as:

.. code-block:: shell

    brew install python@3.9

Windows
=======

As for MacOS, here is the official documentation: `Using Python on Windows`_.

For Windows' users the stable release is available from `downloads`_. Just
download the installer and proceed to common steps to install software.

.. important:: It's recommended to **Add Python3.x to PATH**, this will avoid
               problems at the beginning of your journey with Python

.. figure:: https://docs.python.org/3/_images/win_installer.png
    :width: 600
    :align: center

    Python installer first page

Going on with **Install Now**:

- Python will be installed to your user directory
- Python Launcher will be installed according to the option at the bottom
  of the page

Using **Customize installation** will perform an *all-users* installation.

Removing the MAX_PATH Limitation
--------------------------------

Windows historically has limited path lengths to 260 characters. This meant
that paths longer than this would not resolve and errors would result. In the
latest versions of Windows, this limitation can be expanded to approximately
32,000 characters. This allows the open() function, the os module and most
other path functionality to accept and return paths longer than 260 characters.

You will need PC administrator assistance to perform this action.

Install from the Microsoft Store
--------------------------------

You can install from the Microsoft Store in two steps:

#.  Open the Microsoft Store app and search for ``Python``
    The result should look like:

    .. figure:: /../assets/img/microsoft-store-search.png
        :align: center

        Microsoft Store - search results for "Python"

    Select ``Python 3.9`` or the higher available version.

#.  Click **GET** and wait until the installer is downloaded. The installation
    process should run automatically. Follow the installer's instructions.

    .. figure:: /../assets/img/microsoft-store-get.png
        :scale: 50%
        :align: center

Online Interpreters
===================

Installing or updating Python on your computer is the first step to becoming
a Python programmer :cite:`realpython:install-and-setup`.

But if you cannot install Python at the moment for some reason, are can go
with online interpreters. `repl.it <https://replit.com/>`_ provides the ability
to create and store Python scripts (they are called *repl* here) for free.

.. _formulae: https://formulae.brew.sh/formula/
.. _Using Python on Windows: https://docs.python.org/3/using/windows.html
.. _Using Python on a Mac: https://docs.python.org/3/using/mac.html
.. _downloads: https://www.python.org/downloads/