Download latest Python MSI from python.org/downloads

Get-PythonMSI.ps1

Function Test-Url {
    [CmdletBinding()]
    
    param (
        [Parameter(Mandatory=$true)]
        [String] $Url,

        [Parameter()]
        [Switch] $ReturnUri
    )

    Process {
        if ([system.uri]::IsWellFormedUriString($Url,[System.UriKind]::Absolute)) {
            $true
        } else {
            $false
        }
    }
}

Function Get-PythonMSI {
    [CmdletBinding()]
    param (
        [Parameter(ParameterSetName='Download')]
        [Switch]$DownloadLatest,

        [Parameter(ParameterSetName='Download',Mandatory=$false)]
        [String]$DownloadPath = "$env:USERPROFILE\Downloads"

    )

    Process {
        $Msi = @()
        $doc = Invoke-WebRequest -Uri 'https://www.python.org/downloads'
        foreach ($href in ($doc.links.href -ne '')) {
            if ((Test-Url -Url $href) -and $href.EndsWith('.msi')) {
                $uri = [System.uri]$href
                $Msi += New-Object -TypeName PSObject -Property @{
                    "Url" = $href
                    "Version" = $Uri.Segments[-2].Replace('/','')
                }
            }   
        }

        if ($DownloadLatest) {
            $MsiToInstall = $msi | Sort -Property Version -Descending | Select -First 1
            Start-BitsTransfer -Source $MsiToInstall.Url -Destination $DownloadPath
        } else {
            $Msi
        }
    }
}

#Usage
#get a list of all MSIs
Get-PythonMSI

#Download the latest MSI
Get-PythonMSI -DownloadLatest

#Download the latest MSI to a specific destination
Get-PythonMSI -DownloadLatest -DownloadPath C:\Downloads