I’m going to talk here about various techniques regarding the Django’s settings.

Let’s assume the following project layout:
.
├── __init__.py
├── manage.py
├── settings
└── urls.py

How do I use custom settings or overwrite existing ones on my development machine ?

Answer 1

Create your custom settings file under the same parent as the existing settings.py. Let’s name the new file settings_local.py
At the bottom of settings.py, add the following:

try:
    from settings_local import *
except ImportError:
    pass

Pros

• no need to change the manage.py or the wsgi file in order to apply the new settings

Cons

• hard/impossible to use different settings for different environment

 Answer 2 (preferred)

Create a new directory called “settings” and move the existing setting file there. Then make a different file for each type of environment.
.
├── __init__.py
├── manage.py
├── settings
│   ├── __init__.py
│   ├── development.py
│   ├── production.py
│   └── settings.py
└── urls.py

settings.py will include the default Django settings, probably the file created by django-admin.py
development.py will hold settings/overwrites needed for the development environment.
The extra settings files (production.py, development.py, etc) will extend the existing settings.py (or another parent file which in turn extends settings.py) and add their own settings customizations.
This could be your development.py file:

from .production import *
DEBUG = True
TEMPLATE_DEBUG = True
DJANGO_SERVE_PUBLIC = True
PREPEND_WWW = False
SEND_BROKEN_LINK_EMAILS = False
# APP: debug_toolbar
MIDDLEWARE_CLASSES += (
"debug_toolbar.middleware.DebugToolbarMiddleware",
)
INSTALLED_APPS += (
"debug_toolbar",
)
DEBUG_TOOLBAR_CONFIG = {
'INTERCEPT_REDIRECTS': False,
}
TEMPLATE_CONTEXT_PROCESSORS += [
'django.core.context_processors.debug'
]

Where production.py is:

from .settings import *
import os.path
PROJECT_ROOT = os.path.join(os.path.abspath(os.path.dirname(__file__)), '../')
DEBUG = False
TEMPLATE_DEBUG = False

Once your settings setup is in place, all you have to do is change manage.py and your WSGI file.
The manage.py file could now look like this:

#!/usr/bin/env python
from django.core.management import execute_manager
import sys, os
PROJECT_ROOT = os.path.abspath(os.path.dirname(__file__))
sys.path.insert(0, PROJECT_ROOT)
try:
import settings.development # Assumed to be in the same directory.
except ImportError, e:
import sys
sys.stderr.write("Error: Can't find the file 'settings.py' in the directory containing %r. It appears you've customized things. You'll have to run django-admin.py, passing it your settings module. (If the file settings.py does indeed exist, it's causing an ImportError somehow.) " % __file__)
sys.exit(1)
if __name__ == "__main__":
execute_manager(settings.development)

In the same time, your WSGI file would use settings.production:

os.environ[“DJANGO_SETTINGS_MODULE”] = “settings.production”
Pros

• easy to create settings for each of your environments (production, development, etc)
• it’s a great way to keep your settings organized, easy to find and edit.
• easier to reuse your settings for other projects. For example, we could use the same development.py file (as shown above) with other production.py settings.

Cons

• you have to change the manage.py and the WSGI file, which might not be possible on your client server.

 Other Django settings tips

• do not use your project name in the settings, i.e. use ROOT_URLCONF = ‘urls’ and not ROOT_URLCONF = ‘myproject.urls’, use INSTALLED_APPS = (“appname”,) and not INSTALLED_APPS = (“myproject.appname”, ). You will then be able to easily move settings and applications between one project to another
• use calculated paths for TEMPLATE_DIR, MEDIA_ROOT, STATIC_ROOT etc, i.e. PROJECT_ROOT = os.path.abspath(os.path.dirname(__file__)) and then MEDIA_ROOT = os.path.join(PROJECT_ROOT, “media”)