Tuesday, June 7, 2011

Django: Executing manage.py from Anywhere

One nice convenience would be to have a way to call manage.py from anywhere within a virtual environment.  For example, if I want to execute 'manage.py shell', it would be nice to be able to execute that from anywhere rather than having to change directory to where manage.py lives.

We can already run management commands from anywhere using django-admin by utilizing the --settings flag, but doing this requires a lot of typing. And wrapping the django-admin in a shell script seems inelegant somehow.

Instead, I wrote a small python script based off of manage.py.  This can be placed in the ./bin directory in the virtualenv.  The DjangoManageSettings object is meant to be customized on a per project basis, and I intend to make it so it can be passed in from a file configuration somewhere.

Anyway, thought I would share.  I'm curious to see other approaches to this.

# ---------- ${VIRTUAL_ENV}/bin/django_manage.py -------------------------
#!/usr/bin/env python

import os, sys
from django.core.management import execute_manager

class DjangoManageSettings(object):

    def __init__(self):
        self.VENV_ROOT = os.getenv("VIRTUAL_ENV")
        # The name of the module that settings.py resides in
        # The path to the directory where the Django project lives. 
        # I made it relative to the virtualenv root. 
        self.PROJECT_PARENT_PATH = os.path.join(self.VENV_ROOT, "app")
        # The name of the django settings model in the project

dm_settings = DjangoManageSettings()

if not dm_settings.VENV_ROOT:
    print("A virtual environment must be activated before using this script.")

sys.path.insert(0, os.path.join(dm_settings.PROJECT_PARENT_PATH))
mod = __import__(dm_settings.PROJECT_NAME, globals(), locals(), 
settings = getattr(mod, dm_settings.SETTINGS_MODULE_NAME)

if __name__ == "__main__":


  1. You don't really have to pass the settings module as argument for `django-admin.py` on each call. Command `django-admin.py` also looks for the environment variable `DJANGO_SETTINGS_MODULE` to locate your settings module. And thus every virtualenv have a script named `activate` which gets invoked when activating the virtualenv, you can simple export `DJANGO_SETTINGS_MODULE` with the proper value.

    `django-admin.py` even allows you to use other names for your settings module than "settings". I maintain a separate settings module for each environment e.g. "project.settings.devel", "project.settings.prod".

  2. Thanks the advice - didn't think of using the DJANGO_SETTINGS_MODULE, but that seems like a simpler solution. (To get this to work, I also needed to put my project on the Python Path.)
    Thank you again, Joe