<# | |
.Synopsis | |
Activate a Python virtual environment for the current PowerShell session. | |
.Description | |
Pushes the python executable for a virtual environment to the front of the | |
$Env:PATH environment variable and sets the prompt to signify that you are | |
in a Python virtual environment. Makes use of the command line switches as | |
well as the `pyvenv.cfg` file values present in the virtual environment. | |
.Parameter VenvDir | |
Path to the directory that contains the virtual environment to activate. The | |
default value for this is the parent of the directory that the Activate.ps1 | |
script is located within. | |
.Parameter Prompt | |
The prompt prefix to display when this virtual environment is activated. By | |
default, this prompt is the name of the virtual environment folder (VenvDir) | |
surrounded by parentheses and followed by a single space (ie. '(.venv) '). | |
.Example | |
Activate.ps1 | |
Activates the Python virtual environment that contains the Activate.ps1 script. | |
.Example | |
Activate.ps1 -Verbose | |
Activates the Python virtual environment that contains the Activate.ps1 script, | |
and shows extra information about the activation as it executes. | |
.Example | |
Activate.ps1 -VenvDir C:\Users\MyUser\Common\.venv | |
Activates the Python virtual environment located in the specified location. | |
.Example | |
Activate.ps1 -Prompt "MyPython" | |
Activates the Python virtual environment that contains the Activate.ps1 script, | |
and prefixes the current prompt with the specified string (surrounded in | |
parentheses) while the virtual environment is active. | |
.Notes | |
On Windows, it may be required to enable this Activate.ps1 script by setting the | |
execution policy for the user. You can do this by issuing the following PowerShell | |
command: | |
PS C:\> Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser | |
For more information on Execution Policies: | |
https://go.microsoft.com/fwlink/?LinkID=135170 | |
#> | |
Param( | |
[Parameter(Mandatory = $false)] | |
[String] | |
$VenvDir, | |
[Parameter(Mandatory = $false)] | |
[String] | |
$Prompt | |
) | |
<# Function declarations --------------------------------------------------- #> | |
<# | |
.Synopsis | |
Remove all shell session elements added by the Activate script, including the | |
addition of the virtual environment's Python executable from the beginning of | |
the PATH variable. | |
.Parameter NonDestructive | |
If present, do not remove this function from the global namespace for the | |
session. | |
#> | |
function global:deactivate ([switch]$NonDestructive) { | |
# Revert to original values | |
# The prior prompt: | |
if (Test-Path -Path Function:_OLD_VIRTUAL_PROMPT) { | |
Copy-Item -Path Function:_OLD_VIRTUAL_PROMPT -Destination Function:prompt | |
Remove-Item -Path Function:_OLD_VIRTUAL_PROMPT | |
} | |
# The prior PYTHONHOME: | |
if (Test-Path -Path Env:_OLD_VIRTUAL_PYTHONHOME) { | |
Copy-Item -Path Env:_OLD_VIRTUAL_PYTHONHOME -Destination Env:PYTHONHOME | |
Remove-Item -Path Env:_OLD_VIRTUAL_PYTHONHOME | |
} | |
# The prior PATH: | |
if (Test-Path -Path Env:_OLD_VIRTUAL_PATH) { | |
Copy-Item -Path Env:_OLD_VIRTUAL_PATH -Destination Env:PATH | |
Remove-Item -Path Env:_OLD_VIRTUAL_PATH | |
} | |
# Just remove the VIRTUAL_ENV altogether: | |
if (Test-Path -Path Env:VIRTUAL_ENV) { | |
Remove-Item -Path env:VIRTUAL_ENV | |
} | |
# Just remove VIRTUAL_ENV_PROMPT altogether. | |
if (Test-Path -Path Env:VIRTUAL_ENV_PROMPT) { | |
Remove-Item -Path env:VIRTUAL_ENV_PROMPT | |
} | |
# Just remove the _PYTHON_VENV_PROMPT_PREFIX altogether: | |
if (Get-Variable -Name "_PYTHON_VENV_PROMPT_PREFIX" -ErrorAction SilentlyContinue) { | |
Remove-Variable -Name _PYTHON_VENV_PROMPT_PREFIX -Scope Global -Force | |
} | |
# Leave deactivate function in the global namespace if requested: | |
if (-not $NonDestructive) { | |
Remove-Item -Path function:deactivate | |
} | |
} | |
<# | |
.Description | |
Get-PyVenvConfig parses the values from the pyvenv.cfg file located in the | |
given folder, and returns them in a map. | |
For each line in the pyvenv.cfg file, if that line can be parsed into exactly | |
two strings separated by `=` (with any amount of whitespace surrounding the =) | |
then it is considered a `key = value` line. The left hand string is the key, | |
the right hand is the value. | |
If the value starts with a `'` or a `"` then the first and last character is | |
stripped from the value before being captured. | |
.Parameter ConfigDir | |
Path to the directory that contains the `pyvenv.cfg` file. | |
#> | |
function Get-PyVenvConfig( | |
[String] | |
$ConfigDir | |
) { | |
Write-Verbose "Given ConfigDir=$ConfigDir, obtain values in pyvenv.cfg" | |
# Ensure the file exists, and issue a warning if it doesn't (but still allow the function to continue). | |
$pyvenvConfigPath = Join-Path -Resolve -Path $ConfigDir -ChildPath 'pyvenv.cfg' -ErrorAction Continue | |
# An empty map will be returned if no config file is found. | |
$pyvenvConfig = @{ } | |
if ($pyvenvConfigPath) { | |
Write-Verbose "File exists, parse `key = value` lines" | |
$pyvenvConfigContent = Get-Content -Path $pyvenvConfigPath | |
$pyvenvConfigContent | ForEach-Object { | |
$keyval = $PSItem -split "\s*=\s*", 2 | |
if ($keyval[0] -and $keyval[1]) { | |
$val = $keyval[1] | |
# Remove extraneous quotations around a string value. | |
if ("'""".Contains($val.Substring(0, 1))) { | |
$val = $val.Substring(1, $val.Length - 2) | |
} | |
$pyvenvConfig[$keyval[0]] = $val | |
Write-Verbose "Adding Key: '$($keyval[0])'='$val'" | |
} | |
} | |
} | |
return $pyvenvConfig | |
} | |
<# Begin Activate script --------------------------------------------------- #> | |
# Determine the containing directory of this script | |
$VenvExecPath = Split-Path -Parent $MyInvocation.MyCommand.Definition | |
$VenvExecDir = Get-Item -Path $VenvExecPath | |
Write-Verbose "Activation script is located in path: '$VenvExecPath'" | |
Write-Verbose "VenvExecDir Fullname: '$($VenvExecDir.FullName)" | |
Write-Verbose "VenvExecDir Name: '$($VenvExecDir.Name)" | |
# Set values required in priority: CmdLine, ConfigFile, Default | |
# First, get the location of the virtual environment, it might not be | |
# VenvExecDir if specified on the command line. | |
if ($VenvDir) { | |
Write-Verbose "VenvDir given as parameter, using '$VenvDir' to determine values" | |
} | |
else { | |
Write-Verbose "VenvDir not given as a parameter, using parent directory name as VenvDir." | |
$VenvDir = $VenvExecDir.Parent.FullName.TrimEnd("\\/") | |
Write-Verbose "VenvDir=$VenvDir" | |
} | |
# Next, read the `pyvenv.cfg` file to determine any required value such | |
# as `prompt`. | |
$pyvenvCfg = Get-PyVenvConfig -ConfigDir $VenvDir | |
# Next, set the prompt from the command line, or the config file, or | |
# just use the name of the virtual environment folder. | |
if ($Prompt) { | |
Write-Verbose "Prompt specified as argument, using '$Prompt'" | |
} | |
else { | |
Write-Verbose "Prompt not specified as argument to script, checking pyvenv.cfg value" | |
if ($pyvenvCfg -and $pyvenvCfg['prompt']) { | |
Write-Verbose " Setting based on value in pyvenv.cfg='$($pyvenvCfg['prompt'])'" | |
$Prompt = $pyvenvCfg['prompt']; | |
} | |
else { | |
Write-Verbose " Setting prompt based on parent's directory's name. (Is the directory name passed to venv module when creating the virtual environment)" | |
Write-Verbose " Got leaf-name of $VenvDir='$(Split-Path -Path $venvDir -Leaf)'" | |
$Prompt = Split-Path -Path $venvDir -Leaf | |
} | |
} | |
Write-Verbose "Prompt = '$Prompt'" | |
Write-Verbose "VenvDir='$VenvDir'" | |
# Deactivate any currently active virtual environment, but leave the | |
# deactivate function in place. | |
deactivate -nondestructive | |
# Now set the environment variable VIRTUAL_ENV, used by many tools to determine | |
# that there is an activated venv. | |
$env:VIRTUAL_ENV = $VenvDir | |
if (-not $Env:VIRTUAL_ENV_DISABLE_PROMPT) { | |
Write-Verbose "Setting prompt to '$Prompt'" | |
# Set the prompt to include the env name | |
# Make sure _OLD_VIRTUAL_PROMPT is global | |
function global:_OLD_VIRTUAL_PROMPT { "" } | |
Copy-Item -Path function:prompt -Destination function:_OLD_VIRTUAL_PROMPT | |
New-Variable -Name _PYTHON_VENV_PROMPT_PREFIX -Description "Python virtual environment prompt prefix" -Scope Global -Option ReadOnly -Visibility Public -Value $Prompt | |
function global:prompt { | |
Write-Host -NoNewline -ForegroundColor Green "($_PYTHON_VENV_PROMPT_PREFIX) " | |
_OLD_VIRTUAL_PROMPT | |
} | |
$env:VIRTUAL_ENV_PROMPT = $Prompt | |
} | |
# Clear PYTHONHOME | |
if (Test-Path -Path Env:PYTHONHOME) { | |
Copy-Item -Path Env:PYTHONHOME -Destination Env:_OLD_VIRTUAL_PYTHONHOME | |
Remove-Item -Path Env:PYTHONHOME | |
} | |
# Add the venv to the PATH | |
Copy-Item -Path Env:PATH -Destination Env:_OLD_VIRTUAL_PATH | |
$Env:PATH = "$VenvExecDir$([System.IO.Path]::PathSeparator)$Env:PATH" | |