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

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 :)