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