Downloading and Installing Python via a Batch file

Question

I am attempting to use PowerShell to download the Python 3 installer from the Python website into a specific directory, then silently run/install the .exe in that same directory and then add the appropriate directory to my system's PATH variable.

So far I have come up with:

start cmd /k powershell -Command "(New-Object Net.WebClient).DownloadFile('https://www.python.org/ftp/python/3.6.2/python-3.6.2.exe', 'C:/Tools/python-3.6.2.exe')" && 
c:\Tools\python-3.6.2.exe /quiet InstallAllUsers=1 PrependPath=1 Include_test=0 TargetDir=c:\Tools\Python362 &&
setx path "%PATH%;C:\Tools\Python362\" /M

Unfortunately this does not work. The command window will open, and then immediately quit. I have run each of these commands separately, and when I do so they work, however when I try to run them sequentially in the same file it does not work. Any assistance would be incredibly appreciated.

Note: I believe the problem stems from the use of &&, because if I use & the CMD prompt will persist, and execute. However, this does not help me since I need the second command to execute after the first one has finished or else there is no .exe for the second command to run. I am hoping this is just a syntactic error as I am very new to creating batch files and working with the windows command line.

Answer 1

I'd do it all in Powershell, personally.

I'd be tempted to put it in a script, like this:

[CmdletBinding()] Param(
    $pythonVersion = "3.6.2"
    $pythonUrl = "https://www.python.org/ftp/python/$pythonVersion/python-$pythonVersion.exe"
    $pythonDownloadPath = 'C:\Tools\python-$pythonVersion.exe'
    $pythonInstallDir = "C:\Tools\Python$pythonVersion"
)

(New-Object Net.WebClient).DownloadFile($pythonUrl, $pythonDownloadPath)
& $pythonDownloadPath /quiet InstallAllUsers=1 PrependPath=1 Include_test=0 TargetDir=$pythonInstallDir
if ($LASTEXITCODE -ne 0) {
    throw "The python installer at '$pythonDownloadPath' exited with error code '$LASTEXITCODE'"
}
# Set the PATH environment variable for the entire machine (that is, for all users) to include the Python install dir
[Environment]::SetEnvironmentVariable("PATH", "${env:path};${pythonInstallDir}", "Machine")

Then you can call the script from cmd.exe like this:

Powershell.exe -File X:\Path\to\Install-Python.ps1

The Param() block defines defaults for the Python version, the URL to download it from, the place to save it, and the place to install it to, but lets you override these options if that ever becomes useful. You might pass those arguments like this:

Powershell.exe -File X:\Path\to\Install-Python.ps1 -version 3.4.0 -pythonInstallDir X:\Somewhere\Else\Python3.4.0

That said, you absolutely can just do a one-liner in pure Powershell as well. From your description, I don't think you should need to do the start cmd /k prefix - you should be able to just call Powershell.exe directly, like this:

powershell -command "(New-Object Net.WebClient).DownloadFile('https://www.python.org/ftp/python/3.6.2/python-3.6.2.exe', 'C:/Tools/python-3.6.2.exe'); & c:\Tools\python-3.6.2.exe /quiet InstallAllUsers=1 PrependPath=1 Include_test=0 TargetDir=c:\Tools\Python362; [Environment]::SetEnvironmentVariable('PATH', ${env:path} + ';C:\Tools\Python362', 'Machine')"

Answer 2

Do it all in PowerShell including installing a library.

# This is the link to download Python 3.6.7 from Python.org
# See https://www.python.org/downloads/
$pythonUrl = "https://www.python.org/ftp/python/3.6.7/python-3.6.7-amd64.exe"

# This is the directory that the exe is downloaded to
$tempDirectory = "C:\temp_provision\"

# Installation Directory
# Some packages look for Python here
$targetDir = "C:\Python36"

# create the download directory and get the exe file
$pythonNameLoc = $tempDirectory + "python367.exe"
New-Item -ItemType directory -Path $tempDirectory -Force | Out-Null
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
(New-Object System.Net.WebClient).DownloadFile($pythonUrl, $pythonNameLoc)

# These are the silent arguments for the install of python
# See https://docs.python.org/3/using/windows.html
$Arguments = @()
$Arguments += "/i"
$Arguments += 'InstallAllUsers="1"'
$Arguments += 'TargetDir="' + $targetDir + '"'
$Arguments += 'DefaultAllUsersTargetDir="' + $targetDir + '"'
$Arguments += 'AssociateFiles="1"'
$Arguments += 'PrependPath="1"'
$Arguments += 'Include_doc="1"'
$Arguments += 'Include_debug="1"'
$Arguments += 'Include_dev="1"'
$Arguments += 'Include_exe="1"'
$Arguments += 'Include_launcher="1"'
$Arguments += 'InstallLauncherAllUsers="1"'
$Arguments += 'Include_lib="1"'
$Arguments += 'Include_pip="1"'
$Arguments += 'Include_symbols="1"'
$Arguments += 'Include_tcltk="1"'
$Arguments += 'Include_test="1"'
$Arguments += 'Include_tools="1"'
$Arguments += 'Include_launcher="1"'
$Arguments += 'Include_launcher="1"'
$Arguments += 'Include_launcher="1"'
$Arguments += 'Include_launcher="1"'
$Arguments += 'Include_launcher="1"'
$Arguments += 'Include_launcher="1"'
$Arguments += "/passive"

#Install Python
Start-Process $pythonNameLoc -ArgumentList $Arguments -Wait

Function Get-EnvVariableNameList {
    [cmdletbinding()]
    $allEnvVars = Get-ChildItem Env:
    $allEnvNamesArray = $allEnvVars.Name
    $pathEnvNamesList = New-Object System.Collections.ArrayList
    $pathEnvNamesList.AddRange($allEnvNamesArray)
    return ,$pathEnvNamesList
}

Function Add-EnvVarIfNotPresent {
Param (
[string]$variableNameToAdd,
[string]$variableValueToAdd
   ) 
    $nameList = Get-EnvVariableNameList
    $alreadyPresentCount = ($nameList | Where{$_ -like $variableNameToAdd}).Count
    if ($alreadyPresentCount -eq 0)
    {
    [System.Environment]::SetEnvironmentVariable($variableNameToAdd, $variableValueToAdd, [System.EnvironmentVariableTarget]::Machine)
    [System.Environment]::SetEnvironmentVariable($variableNameToAdd, $variableValueToAdd, [System.EnvironmentVariableTarget]::Process)
    [System.Environment]::SetEnvironmentVariable($variableNameToAdd, $variableValueToAdd, [System.EnvironmentVariableTarget]::User)
        $message = "Enviromental variable added to machine, process and user to include $variableNameToAdd"
    }
    else
    {
        $message = 'Environmental variable already exists. Consider using a different function to modify it'
    }
    Write-Information $message
}

Function Get-EnvExtensionList {
    [cmdletbinding()]
    $pathExtArray =  ($env:PATHEXT).Split("{;}")
    $pathExtList = New-Object System.Collections.ArrayList
    $pathExtList.AddRange($pathExtArray)
    return ,$pathExtList
}

Function Add-EnvExtension {
Param (
[string]$pathExtToAdd
   ) 
    $pathList = Get-EnvExtensionList
    $alreadyPresentCount = ($pathList | Where{$_ -like $pathToAdd}).Count
    if ($alreadyPresentCount -eq 0)
    {
        $pathList.Add($pathExtToAdd)
        $returnPath = $pathList -join ";"
        [System.Environment]::SetEnvironmentVariable('pathext', $returnPath, [System.EnvironmentVariableTarget]::Machine)
        [System.Environment]::SetEnvironmentVariable('pathext', $returnPath, [System.EnvironmentVariableTarget]::Process)
        [System.Environment]::SetEnvironmentVariable('pathext', $returnPath, [System.EnvironmentVariableTarget]::User)
        $message = "Path extension added to machine, process and user paths to include $pathExtToAdd"
    }
    else
    {
        $message = 'Path extension already exists'
    }
    Write-Information $message
}

Function Get-EnvPathList {
    [cmdletbinding()]
    $pathArray =  ($env:PATH).Split("{;}")
    $pathList = New-Object System.Collections.ArrayList
    $pathList.AddRange($pathArray)
    return ,$pathList
}

Function Add-EnvPath {
Param (
[string]$pathToAdd
   ) 
    $pathList = Get-EnvPathList
    $alreadyPresentCount = ($pathList | Where{$_ -like $pathToAdd}).Count
    if ($alreadyPresentCount -eq 0)
    {
        $pathList.Add($pathToAdd)
        $returnPath = $pathList -join ";"
        [System.Environment]::SetEnvironmentVariable('path', $returnPath, [System.EnvironmentVariableTarget]::Machine)
        [System.Environment]::SetEnvironmentVariable('path', $returnPath, [System.EnvironmentVariableTarget]::Process)
        [System.Environment]::SetEnvironmentVariable('path', $returnPath, [System.EnvironmentVariableTarget]::User)
        $message = "Path added to machine, process and user paths to include $pathToAdd"
    }
    else
    {
        $message = 'Path already exists'
    }
    Write-Information $message
}

Add-EnvExtension '.PY'
Add-EnvExtension '.PYW'
Add-EnvPath 'C:\Python36\'

# Install a library using Pip
python -m pip install numpy