RunScript

synopsis

Runs a script in the Django context.

Introduction

The runscript command lets you run an arbitrary set of python commands within the Django context. It offers the same usability and functionality as running a set of commands in shell accessed by:

$ python manage.py shell

Getting Started

This example assumes you have followed the tutorial for Django 1.8+, and created a polls app containing a Question model. We will create a script that deletes all of the questions from the database.

To get started create a scripts directory in your project root, next to manage.py:

$ mkdir scripts
$ touch scripts/__init__.py

Note: The __init__.py file is necessary so that the folder is picked up as a python package.

Next, create a python file with the name of the script you want to run within the scripts directory:

$ touch scripts/delete_all_questions.py

This file must implement a run() function. This is what gets called when you run the script. You can import any models or other parts of your django project to use in these scripts.

For example:

# scripts/delete_all_questions.py

from polls.models import Question

def run():
    # Fetch all questions
    questions = Question.objects.all()
    # Delete questions
    questions.delete()

Note: You can put a script inside a scripts folder in any of your apps too.

Usage

To run any script you use the command runscript with the name of the script that you want to run.

For example:

$ python manage.py runscript delete_all_questions

Note: The command first checks for scripts in your apps i.e. app_name/scripts folder and runs them before checking for and running scripts in the project_root/scripts folder. You can have multiple scripts with the same name and they will all be run sequentially.

Passing arguments

You can pass arguments from the command line to your script by passing a space separated list of values with --script-args. For example:

$ python manage.py runscript delete_all_questions --script-args staleonly

The list of argument values gets passed as arguments to your run() function. For example:

# scripts/delete_all_questions.py
from datetime import timedelta

from django.utils import timezone

from polls.models import Question

def run(*args):
    # Get all questions
    questions = Question.objects.all()
    if 'staleonly' in args:
        # Only get questions more than 100 days old
        questions = questions.filter(pub_date__lt=timezone.now() - timedelta(days=100))
    # Delete questions
    questions.delete()

Setting execution directory

You can set scripts execution directory using --chdir option or settings.RUNSCRIPT_CHDIR. You can also set scripts execution directory policy using --dir-policy option or settings.RUNSCRIPT_CHDIR_POLICY.

It can be one of the following:

  • none - start all scripts in current directory.

  • each - start all scripts in their directories.

  • root - start all scripts in BASE_DIR directory.

Assume this simplified directory structure:

django_project_dir/
├-first_app/
│ └-scripts/
│   ├-first_script.py
├-second_app/
│ └-scripts/
│   ├-second_script.py
├-manage.py
├-other_folder/
│ └-some_file.py

Assume you are in other_folder directory. You can set execution directory for both scripts using this command:

$ python ../manage.py runscript first_script second_script --chdir /django_project_dir/second_app
# scripts will be executed from second_app directory

You can run both scripts with NONE policy using this command:

$ python ../manage.py runscript first_script second_script --dir-policy none
  # scripts will be executed from other_folder directory

You can run both scripts with EACH policy using this command:

$ python ../manage.py runscript first_script second_script --dir-policy each
  # first_script will be executed from first_app and second script will be executed from second_app

You can run both scripts with ROOT policy using this command:

$ python ../manage.py runscript first_script second_script --dir-policy root
  # scripts will be executed from django_project_dir directory

Errors and exit codes

If an exception is encountered the execution of the scripts will stop, a traceback is shown and the command will return an exit code.

To control the exit-code you can either use CommandError(“something went terribly wrong”, returncode=123) in your script or has the run(…) function return the exit_code. Where any exit code other then 0 will indicate failure, just like regular shell commands.

This means you can use runscript in your CI/CD pipelines or other automated scripts and it should behave like any other shell command.

Continue on errors

If you want runscript to continue running scripts even if errors occurs you can set -c:

$ python manage.py runscript delete_all_questions another_script --continue-on-error

This will continue running ‘another_script’ even if an exception was raised or exit code was returned in ‘delete_all_questions’.

When all the scripts has been run runscript will exit with the last non-zero exit code.

Note: It is possible to do raise CommandError(…, returncode=0) which will lead to an exception with exit code 0.

Debugging

If an exception occurs you will get a traceback by default. You can use CommandError in the same way as with other custom management commands.

To get a traceback from a CommandError specify --traceback. For example:

$ python manage.py runscript delete_all_questions --traceback

If you do not want to see tracebacks at all you can specify:

$ python manage.py runscript delete_all_questions --no-traceback