Automatically detect .python-version and switch in/out of enviroment when changing directories

[sam-val]

Like title, current version (v0.6.2) doesn't do this. It'd be great if we also have it too like the original.

[arzkar]

The current behavior is to activate the env if you open a shell from within a directory which has the .python-version.
To automatically look for the env in every directory, I will need to add an Event Watcher which will check for the .python-version every time we change the directory, might add an overhead to the shell but I will look into it when I get the time.

[bucefalog]

If anybody lands on this page, adding the following lines to powershell's profile might work as a provisory solution:

# ACTIVE PYTHON ENVIRONMENT AUTOMATICALLY:
$script_file = "$HOME/.config/powershell/set_location_proxy.ps1"
#  NOTE: the following should only be executed once and the regex substitution may fail in the future
$temp_var = New-Object System.Management.Automation.CommandMetadata (Get-Command Set-Location)
$temp_var = [System.Management.Automation.ProxyCommand]::Create($temp_var)
$temp_var = ($temp_var) -replace '(\s*)\$steppablePipeline\.End\(\)', "`${1}`$steppablePipeline.End()`r`n`${1}pyenv-venv init root" 
"function Set-Location {`n" | Set-Content -Path "$script_file" 
$temp_var | Add-Content -Path "$script_file" 
"`n}" | Add-Content -Path "$script_file"
. "$script_file"

The script is creating a proxy to the Set-Location function and sourcing it.
The proxy replaces the powershell default function and works with any command that uses the function (including cd and zoxide).
It may also be useful to modify the code to deactivate the current environment when moving into a folder with no python version found.

[Helveg]

@bucefalog your snippet works, but it errors out if the $script_file path doesn't exist. It seems that $HOME/.config/powershell is not guaranteed to exist. When I created it your snippet worked as expected.

[kiber-io]

@bucefalog hi! Thanks for the excellent tip!
I tried to refine your script to automatically deactivate venv when exiting the folder. I also corrected the error due to the lack of a powershell folder and made sure that the code was executed exactly only once - when there was no script yet. Works on at least PowerShell 7.

# # ACTIVE PYTHON ENVIRONMENT AUTOMATICALLY:
$powershellConfigPath = "$HOME/.config/powershell"
$script_file = "$powershellConfigPath/pyenv-venv-auto.ps1"
if (Test-Path -Path $script_file) {
    . "$script_file"
    exit
}
if (-not (Test-Path -Path $powershellConfigPath)) {
    New-Item -Path $powershellConfigPath -ItemType Directory > $null
}
# #  NOTE: the following should only be executed once and the regex substitution may fail in the future
$temp_var = New-Object System.Management.Automation.CommandMetadata (Get-Command Set-Location)
$temp_var = [System.Management.Automation.ProxyCommand]::Create($temp_var)
$temp_var = ($temp_var) -replace '(\s*)\$steppablePipeline\.End\(\)', @'
${1}$steppablePipeline.End()

# pyenv-venv-auto start
if ($global:pyenvVenvPath) {
    if ($pwd.Path.StartsWith($global:pyenvVenvPath) -ne $true) {
        $global:pyenvVenvPath = $null
        pyenv-venv deactivate
    }
}
else {
    $cwd = $pwd.Path
    while ($cwd.length -ne 0) {
        if (Test-Path "$cwd\.python-version") {
            $global:pyenvVenvPath = $cwd
            pyenv-venv init root
            break
        }
        else { $cwd = Split-Path $cwd }
    }
}
# pyenv-venv-auto end
'@
"function Set-Location {`n" | Set-Content -Path "$script_file"
$temp_var | Add-Content -Path "$script_file"
"`n}" | Add-Content -Path "$script_file"
. "$script_file"

It's not a very clean trick, because the file is searched twice, but I didn't find any other way to determine that venv was activated than to search for the file myself.

However, there is a bug from pyenv-venv itself #26 that, when activated via PS, it throws it into cmd, where, of course, this script will no longer work. There are two solutions that you can try to apply locally to solve this problem

[zengdw]

这是我的解决方案，通过在进入或cd进入 退出文件夹时判断是否有.python-version文件来自动执行pyenv-venv init / deactivate来自动激活和退出虚拟环境

function findVersion {
    $currentPath = Get-Location
    $versionFileFound = $false

    # 检查当前目录
    if (Test-Path (Join-Path -Path $currentPath -ChildPath ".python-version")) {
        $versionFileFound = $true
    } 
    if (-not $versionFileFound) {
        # 检查父级目录
        $parentPath = Split-Path -Path $currentPath -Parent
        while ($parentPath -and -not $versionFileFound) {
            if (Test-Path (Join-Path -Path $parentPath -ChildPath ".python-version")) {
                $versionFileFound = $true
                break
            }
            $parentPath = Split-Path -Path $parentPath -Parent
        }
    }
    return $versionFileFound
}

### set-location start ###
function Set-LocationWithAction {
    param(
        [Parameter(ValueFromPipeline=$true)]
        [string]$Path
    )
    
    # 调用原始的 Set-Location 命令
    Microsoft.PowerShell.Management\Set-Location -Path $Path
    
    # 切换目录后要执行的命令
    # 检查当前目录及其父级目录是否存在 .python-version 文件
    $VENV = $env:VIRTUAL_ENV

    $versionFileFound = findVersion
    
    # 根据是否找到 .version 文件执行相应命令
    if ($versionFileFound -and -not $VENV) {
        # "找到 .python-version 文件，执行 pyenv-venv init"
        pyenv-venv init root
        return 
    } 
    if (-not $versionFileFound -and $VENV) {
        pyenv-venv deactivate
    }
}

# 创建别名，替换原有的 cd 命令
Remove-Item alias:\cd -Force -ErrorAction SilentlyContinue
Set-Alias -Name cd -Value Set-LocationWithAction
### set-location end ###

### 初始进入默认执行pyenv-venv init root ###
$versionFileFound = findVersion
if ($versionFileFound) {
    pyenv-venv init root
}
### 初始进入默认执行pyenv-venv init root ###