Run a python script in virtual environment from windows task scheduler

This is more verbose but very easy to understand, and - I found the most important - much easier than using Windows Task Scheduler settings when you have lots of scripts. To create another you just copy the .bat file and change one line.

Save this as a .bat file and point to it under Actions > Start a Program > Program/Script:, with no arguments or "Start in" necessary.

set original_dir=%CD%
set venv_root_dir="C:\Python-Venvs\env-name"
cd %venv_root_dir%
call %venv_root_dir%\Scripts\activate.bat

python your_script.py <arg1> <arg2>

call %venv_root_dir%\Scripts\deactivate.bat
cd %original_dir%
exit /B 1

For an installed command-line program, you can replace python your_script.py <arg1> <arg2> ... with <program name> <arg1> <arg2> ....

In addition it's simple to add another script on the following line, rather than attempting to parse sequential scripts into a one-liner for Task Scheduler.

Though the answer by mx0 above seems to work, I have set up Task Scheduler to run a flask web app on bootup. In this case, manual starting works fine, but manual ending does not. Ending the task kills the cmd.exe task that sets up the virtual environment, but the python.exe continues to run.

The solution that I found worked was from this reddit post which skips the virtual environment activation to call the python executable directly:

path\to\venv\Scripts\python.exe path\to\script.py

I'm not sure how robust this will be, but at least this way ending the task will end the python.exe

I tried with mx0's answer and it works fine as long as your script does not take too long to finish.

I use a different approach in the task scheduler instead using batch files:

In "Program/script" textbox you set the path to Python executable (in my case is inside the virtualenv folder).

"Add arguments" => Just the name of your Python script (name.ppy).

"Start in" => The full path of your Python script (without the name.py).

This way the script runs and wait until the end.

My solution is almost identical to mx0, but I've added an extra step to ensure environment parameters each time. Edit the path/to/app for the app_path variable.

It may be a little redundant to check the environment setup every time, but I like ensuring my environment is set.

Simply schedule the execute_app.bat file or run in the cmd prompt. Deactivate command is not needed unless running from an Anaconda prompt. If you use a full path for path/to/app this file can be executed from any directory. I also have a Linux solution using execute_app.sh file below from a terminal.

This answer has been edited to simplify, and to use variables to make this easier to adapt to new projects.

App structure:
app/bin/app.py
app/bin/execute_app.bat
app/env/requirements.txt

# execute_app.bat file
# windows solution

SETLOCAL
set app_path=path/to/app
set env_path=%app_path%/env
set activ=%env_path%/Scripts/activate.bat
set req=%env_path%/requirements.txt
set app=%app_path%/bin/app.py

py -m venv %env_path% && %activ% && python -m pip install --upgrade pip && pip install -r %req% && python %app%
ENDLOCAL

#!/bin/bash

# execute_app.sh file
# Linux solution

app_path='path/to/app'
env_path=$app_path'/env'
activ=$env_path'/bin/activate'
req=$env_path'/requirements.txt'
app=$app_path'/bin/app.py'

python3 -m venv $env_path &&
. $activ &&
python3 -m pip install --upgrade pip &&
pip install -r $req &&
python $app &&
deactivate

The selected answer for this question is not correct. If you review the comments, you'll see the problem.

My answer builds off of @Nick P's answer (the #2 answer currently). His batch file will work, but you'll want to change the exit code from 1 to 0 if you want Windows Task Scheduler to report the task completed successfully. Also, simply calling the .bat file on the "Program/Script" line will not work. Instead, you need to put the name of your shell as the "Program/Script" to run (for instance, cmd), then put "/c name-of-batch-file.bat" goes in the "Add arguments (optional):" field. And finally, put the path to the batch file (minus the file name) in the "Start in (optional):" field.

It should look something like this:

Solution

Patching the path is all necessary. The quick way would be a bat script that source environment activation script at the beginning

@call PATH_TO_MY_VENV/bin/activate.bat
python app.py

Proceeding Problem

Later you will realize that the python job starts fine, but won't stop when Windows Scheduler stop it.

When taskengine.exe decides to stop the job, the intermediate cmd.exe (bat script) process is killed and the Python.exe will be left straw. since the cmd.exe(bat script) won't signal python.exe to stop on exit.

Final Solution

Let Windows Task Scheduler or taskengine.exe launch python.exe directly without a middle-man script. Previous answers launch python.exe directly with py script, this works for simple modules, but not for some binary module in conda environment.

For binary modules in conda to work, you can create a utility module named e.g. patch_conda_path to patch PATH variable in os.environ based on sys.base_exec_prefix. Copy the patching work that activate.bat does, just in python. below example has been tested for conda virtual environment:

import is, sys
conda_base = sys.base_exec_prefix
subps = [";", "library\\mingw-w64\\bin;", "library\\usr\\bin;", "library\\bin;", "scripts;", "bin;", "condabin;"]
conda_paths = ""
for p in subps :
    _p = os.path.join(conda_base, p)
    if _p in os.environ["PATH"]:
        continue
    else:
        conda_paths += _p
os.environ["PATH'"] = conda_paths + os.environ["PATH"]

Import this module at the beginning of your main script.

import patch_conda_path
... original main script ...

In task scheduler set

• program to ... conda environment path...\python.exe,
• arguments to your py script file name and
• start in to your py script folder.

With the help of ChatGPT I managed to make a small '.bat' script that can activate a virtual environment then run a python script. The neat part is that every element is in the project's root folder so you don't have to think too much about file paths.

Here is first my folder structure:

Project
 - venv
 - update_data.bat
 - extraction.py

and this is the code of the file update_data.bat:

@echo off

rem Get the directory path of the script
for %%I in (%0) do set SCRIPT_DIR=%%~dpI

rem Specify the name of the virtual environment folder
set VENV_FOLDER=venv

rem Set the virtual environment path by combining the script directory and the virtual environment folder
set VENV_PATH=%SCRIPT_DIR%%VENV_FOLDER%

rem Activate the virtual environment
call %VENV_PATH%\Scripts\activate.bat

rem Move to script location
call cd %SCRIPT_DIR%

rem Run your Python script
python extraction.py

rem Deactivate the virtual environment
call %VENV_PATH%\Scripts\deactivate.bat

You can then call the batch file with the task scheduler.