Python script for Django app to access models without using manage.py shell

I'm writing a script to import some model objects into the database my django application uses. In the past I've solved this by running ./manage.py shell and then import myscript. I'm sure there's a better way. I'd like to be able to call a script from anywhere on my HD using python scriptname.py, and in the first few lines of that script it would do whatever imports / other operations necessary so that it can access model objects and behave as though it was run using manage.py shell.

What do I need to add to my script to achieve this?

EDIT:

Based on @Melug's answer, with addition of dynamically setting Python path to address the 'anywhere on my HD' part of the question:

import sys
sys.path.append('c:\\my_projec_src_folder')
from myproject import settings
from django.core.management import setup_environ
setup_environ(settings)

Since Django 1.4 you should avoid using setup_environ(settings) (post by Melug) because it is deprecated. Use the following instead and you will be able to access your model

import os

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "your_project_name.settings")

# your imports, e.g. Django models
from your_project_name.models import Location

# From now onwards start your script..

Here is an example to access and modify your model:

if __name__ == '__main__':    
    # e.g. add a new location
    l = Location()
    l.name = 'Berlin'
    l.save()

    # this is an example to access your model
    locations = Location.objects.all()
    print locations

    # e.g. delete the location
    berlin = Location.objects.filter(name='Berlin')
    print berlin
    berlin.delete()

Example model:

class Location(models.Model):
    name = models.CharField(max_length=100)

To get models loaded too, I had to combine this with this answer, otherwise I get django.core.exceptions.AppRegistryNotReady: Models aren't loaded yet

import os
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "my_project.settings")
import django
django.setup()

As an extra, I add this to the __init__.py of my django projects, it will automatically discover the app name so it is copy/paste-able:

import os


def setup():
    module = os.path.split(os.path.dirname(__file__))[-1]
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "{}.settings".format(module))
    import django
    django.setup()

Then I can just do:

from <app> import setup
setup()

For Django version 1.9 or later you can use this:

import sys
import os
import django

sys.path.append('your_project_directory')
os.environ['DJANGO_SETTINGS_MODULE'] = 'your_project.settings'
django.setup()

from yourapp.models import your_model

so you can use object as same django object:

from myapp.models. import Locations
all_locations = Locations.object.all()
first_location = Locations.object.get(id=1)
print first_location.name()
first_location.save()

I think the best way is to create your custom management command(s). Then you can call manage.py <yourcommand> from anywhere.