Install the Python language interpreter

Install-PythonRelease.ps1

Set-StrictMode -Version Latest
#Requires -Version 7

function Install-PythonRelease {
    <# .SYNOPSIS
    Install the Python language interpreter #>
    param(
        # Install for all users (requires admin)
        [Switch]$AllUsers,
        # Use beta build instead of latest stable
        [Switch]$Beta,
        # Use version X.Y.Z instead of latest stable
        [Version]$Version
    )
    if ($AllUsers -and !(
            [Security.Principal.WindowsIdentity]::GetCurrent().groups -contains 'S-1-5-32-544')) {
        throw 'The AllUsers switch requires administrator privileges.'
    }
    [Uri]$baseURI = 'https://www.python.org/ftp/python/'
    if (!$Version) {
        [Version[]]$versionList = (
            Invoke-WebRequest -NoProxy -Uri $baseURI
        ).links.href.where{ $_ -match '\d+\.\d+\.\d+' }.trim('/')
        [Array]::sort($versionList)
        $Version = $versionList[$($Beta ? -1 : -2)]
    }
    $installDir = $AllUsers ?
    [IO.DirectoryInfo][IO.Path]::Join(
        [Environment]::GetFolderPath('ProgramFiles'), 'Python',
        ('Python {0:d}.{1:d}' -f $Version.Major, $Version.Minor)) :
    [IO.DirectoryInfo][IO.Path]::Join(
        [Environment]::GetFolderPath('LocalApplicationData'), 'Programs', 'Python',
        ('Python{0:d}{1:d}' -f $Version.Major, $Version.Minor))
    if ($installDir.Exists) {
        throw 'Selected python release already exists at {0:s}' -f $installDir
    }
    [Uri]$download = $Beta ?
    '{0:s}{1:s}/{2:s}' -f $baseURI, $Version, (
        Invoke-WebRequest -NoProxy -Uri ('{0:s}{1:s}' -f $baseURI, $Version)
    ).links.href.where{ $_ -match 'amd64\.exe$' }[-1] :
    '{0:s}{1:s}/python-{1:s}-amd64.exe' -f $baseURI, $Version
    $setup = [IO.Path]::Join([IO.Path]::GetTempPath(), $download.Segments[-1])
    Invoke-WebRequest -NoProxy -Uri $download -OutFile $setup
    if (!([IO.FileInfo]$setup).Exists) {
        throw 'Setup file {0:s} not downloaded' -f $setup
    }
    & $setup /quiet InstallAllUsers=$($AllUsers ? 1 : 0) PrependPath=1 Include_launcher=0 Shortcuts=0
    ([IO.FileInfo]$setup).Delete()
}