Trying to Install latest python3 version using powershell script

Question

I am currently installing python3 by hardcoding the version in my script. I am trying to figure out what I can do to always install the latest stable version of python on the windows agent.

$url = "https://www.python.org/ftp/python/3.9.10/python-3.9.10.exe"
$pythonPath = "C:/Program Files/python/python-3.9.10.exe"

If ((Test-Path C:) -and !(Test-Path "C:\Program Files\python"))
{
    New-Item -Path "C:\Program Files\" -Name "python" -ItemType "directory"
}

[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072

Invoke-WebRequest -Uri $url -OutFile $pythonPath

Above is what I am doing currently, this is working fine though but what can I do not to hardcode the version and install the latest stable python version?

Answer 1

Note: If you're on a recent version of Windows 10 or you're on Windows 11, consider using winget.exe to install Python, which automatically targets the latest (stable) version:

winget install python --accept-package-agreements

---

Otherwise , you'll have to resort to web scraping, which is inherently brittle , however (web pages can change).

A pragmatic approach is to scrape https://www.python.org/downloads/ for the first download URL ending in .exe , which is assumed to point to the latest stable version:

if (
  (Invoke-RestMethod 'https://www.python.org/downloads/') -notmatch 
  '\bhref="(?<url>.+?\.exe)"\s*>\s*Download Python (?<version>\d+\.\d+\.\d+)'
) { throw "Could not determine latest Python version and download URL" }

# The automatic $Matches variable contains the results of the regex-
# matching operation.
$url = $Matches.url
$pythonPath = "C:/Program Files/python/python-$($Matches.version).exe"

# ... 

A comparatively more robust, but more cumbersome approach is to scrape https://www.python.org/ftp/python/ instead:

• Since the version numbers listed there also include prerelease versions, additional checks are required to find the latest stable version.
• This answer shows a Unix -focused implementation using a sh ( bash ) shell script.