Setup python, pyenv-win and poetry on Windows

setup-pyenv-poetry-windows.ps1

[CmdletBinding()]
param (
    [Parameter(Mandatory=$true)]
    [string] $PythonVersion
)

$ErrorActionPreference = "Stop"
$ProgressPreference = "SilentlyContinue"
Set-StrictMode -Version Latest


function _runCommand {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory=$true, Position=0)]
        [string] $Command,
        [switch] $PassThru
    )

    if ($PassThru) {
        $res = Invoke-Expression $Command
    }
    else {
        Invoke-Expression $Command
    }

    if ($LASTEXITCODE -ne 0) {
        $msg = "'$Command' reported a non-zero status code [$LASTEXITCODE] - check previous output{0}"
        if ($PassThru) {
            Write-Error ($msg -f "`n$res")
        }
        else {
            Write-Error ($msg -f ".")
        }
    }

    if ($PassThru) {
        return $res
    }
}
function _addToUserPath {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory=$true, Position=0)]
        [string] $AppName,
        [Parameter(Mandatory=$true, Position=1)]
        [string[]] $PathsToAdd
    )

    $pathEntries = [System.Environment]::GetEnvironmentVariable("PATH", [System.EnvironmentVariableTarget]::User) -split ";"

    $pathUpdated = $false
    foreach ($pathToAdd in $PathsToAdd) {
        if ($pathToAdd -notin $pathEntries) {
            $pathEntries = ,$pathToAdd + $pathEntries
            $pathUpdated = $true
        }
    }
    if ($pathUpdated) {
        Write-Host "$($AppName): Updating %PATH%..." -f Green
        # Remove any duplicate or blank entries
        $cleanPaths = $pathEntries | Select-Object -Unique | Where-Object { ![string]::IsNullOrEmpty($_) }

        # Update the user-scoped PATH environment variable
        [System.Environment]::SetEnvironmentVariable("PATH", ($cleanPaths -join ";").TrimEnd(";"), [System.EnvironmentVariableTarget]::User)
        
        # Reload PATH in the current session, so we don't need to restart the console
        $env:PATH = [System.Environment]::GetEnvironmentVariable("PATH", [System.EnvironmentVariableTarget]::User)
    }
    else {
        Write-Host "$($AppName): PATH already setup." -f Cyan
    }
}

Write-Host "#################################################" -f White
Write-Host "## Python, pyenv & poetry Windows setup script ##" -f White
Write-Host "#################################################" -f White

# Install pyenv
if (!(Test-Path $HOME/.pyenv)) {
    # Explicitly check whether running Windows PowerShell, as '$IsWindows' is only available for PowerShell Core
    if ($PSVersionTable.PSEdition -eq 'Desktop' -or $IsWindows) {
        Write-Host "pyenv: Installing for Windows..." -f Green
        & git clone https://github.com/pyenv-win/pyenv-win.git $HOME/.pyenv
        if ($LASTEXITCODE -ne 0) {
            Write-Error "git reported a non-zero status code [$LASTEXITCODE] - check previous output."
        }
    }
    else {
        Write-Error "This script currently only supports Windows."
    }
}
else {
    Write-Host "pyenv: Already installed." -f Cyan
}

# Add pyenv to PATH
_addToUserPath "pyenv" @(
    "$HOME\.pyenv\pyenv-win\bin"
    "$HOME\.pyenv\pyenv-win\shims"
)

# Install default pyenv python version
$pyenvVersions = _runCommand "pyenv versions" -PassThru | Select-String $PythonVersion
if (!($pyenvVersions)) {
    Write-Host "pyenv: Installing python version $PythonVersion..." -f Green
    _runCommand "pyenv install $PythonVersion"
}
else {
    Write-Host "pyenv: Python version $PythonVersion already installed." -f Cyan
}

# Set pyenv global version
$globalPythonVersion = _runCommand "pyenv global" -PassThru
if ($globalPythonVersion -ne $PythonVersion) {
    Write-Host "pyenv: Setting global python version: $PythonVersion" -f Green
    _runCommand "pyenv global $PythonVersion"
}
else {
    Write-Host "pyenv: Global python version already set: $globalPythonVersion" -f Cyan
}

if (!(Get-Command poetry -ErrorAction Ignore)) {
    $downloadPath = "$HOME/Downloads/install-poetry.py"
    Write-Host "python-poetry: Installing..." -f Green
    Invoke-WebRequest -Uri "https://install.python-poetry.org" `
                      -UseBasicParsing `
                      -OutFile $downloadPath
    try {
        _runCommand "pyenv exec python `"$downloadPath`""
    }
    finally {
        Remove-Item $downloadPath
    }
}
else {
    Write-Host "python-poetry: Already installed." -f Cyan
}

# Add poetry to PATH
_addToUserPath "python-poetry" @("$HOME\AppData\Roaming\Python\Scripts")

# Test poetry is available
_runCommand "poetry --version"

Write-Host "####################" -f Green
Write-Host "## Setup Complete ##" -f Green
Write-Host "####################" -f Green

Hi @Fastjur, thanks for the comment.

If you run $PSVersionTable, does this show you are running on PSVersion v5.1? This is the original 'Windows PowerShell' rather than the cross-platform 'PowerShell Core' version - unfortunately $IsWindows is only available in the latter as v5.1 isn't getting updated now. However, the intention was for this script to work on both editions so thanks for letting me know.

I've updated the gist to handle this properly, so hopefully it should work for you now?

Hey @JamesDawson I had issues running the code on Windows 11

PS C:\Users\Shiva.Subramanian\Dropbox\PC\Documents\Shiva\gitrep> ./setup-pyenv-poetry-windows.ps1

cmdlet setup-pyenv-poetry-windows.ps1 at command pipeline position 1
Supply values for the following parameters:
PythonVersion: 3.11.9
#################################################
## Python, pyenv & poetry Windows setup script ##
#################################################
pyenv: Installing for Windows...
Cloning into 'C:\Users\Shiva.Subramanian/.pyenv'...
remote: Enumerating objects: 3227, done.
remote: Counting objects: 100% (517/517), done.
remote: Compressing objects: 100% (118/118), done.
remote: Total 3227 (delta 450), reused 413 (delta 399), pack-reused 2710
Receiving objects: 100% (3227/3227), 3.61 MiB | 9.58 MiB/s, done.
Resolving deltas: 100% (2103/2103), done.
pyenv: Updating %PATH%...
'cscript' is not recognized as an internal or external command,
operable program or batch file.
'cscript' is not recognized as an internal or external command,
operable program or batch file.
'cscript' is not recognized as an internal or external command,
operable program or batch file.
_runCommand : 'pyenv versions' reported a non-zero status code [1] - check previous output
At C:\Users\Shiva.Subramanian\Dropbox\PC\Documents\Shiva\gitrep\setup-pyenv-poetry-windows.ps1:104 char:18
+ $pyenvVersions = _runCommand "pyenv versions" -PassThru | Select-Stri ...
+                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [Write-Error], WriteErrorException
    + FullyQualifiedErrorId : Microsoft.PowerShell.Commands.WriteErrorException,_runCommand

PS C:\Users\Shiva.Subramanian\Dropbox\PC\Documents\Shiva\gitrep>

I checked on another terminal where I was able to run cscript just fine but I suspect there's a bug in the way the path is added (where it loses old configuration so it can't run cscript anymore)

Thanks for the comment @the4amfriend, I've not looked at this specific issue (I run Windows 11 too), but I have just updated the gist to prepend to the path instead of appending, following a comment elsewhere. Can you let me know if this has any effect on your issue?

Sorry @JamesDawson I fixed the path manually and moved on. Not sure if running the script again will impact my current environment?

Sorry @JamesDawson I fixed the path manually and moved on. Not sure if running the script again will impact my current environment?

@the4amfriend how did you fix the path?

I just manually set my path within the same command prompt.

I just manually set my path within the same command prompt.

I tried editing the environment variables through the UI and adding the paths to pyenv-win/bin and pyenv-win/shims (lines 99-100) but that still didn't work.

If it isn't much trouble, could you share the command that you ran in the command prompt to set your path?
What location did you add to PATH? @the4amfriend

I just manually set my path within the same command prompt.

I tried editing the environment variables through the UI and adding the paths to pyenv-win/bin and pyenv-win/shims (lines 99-100) but that still didn't work.

If it isn't much trouble, could you share the command that you ran in the command prompt to set your path? What location did you add to PATH? @the4amfriend

I have the same problem and am quite new to windows. Could use a pointer her too :)