Django snippets

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Warning: This python script is designed for Django 0.96.

It exports data from models quite like the `dumpdata` command, and throws the
data to the standard output.


It fixes glitches with unicode/ascii characters. It looked like the 0.96
handles very badly unicode characters, unless you specify an argument that is
not available via the command line. The simple usage is:

    $ python export_models.py -a <application1> [application2, application3...]

As a plus, it allows you to export only one or several models inside your
application, and not all of them:

    $ python export_models.py application1.MyModelStuff application1.MyOtherModel

Of course, you can specify the output format (serializer) with the -f
(--format) option.

    $ python export_models.py --format=xml application1.MyModel

"""
import sys
import os
from optparse import OptionParser

# You first need to upgrade your python path
SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
sys.path = [os.path.join(SCRIPT_DIR, '../')] + sys.path

# Django
os.environ['DJANGO_SETTINGS_MODULE'] = '#MYPROJECT#.settings'

project_name, settings_name = os.environ['DJANGO_SETTINGS_MODULE'].split('.')

if not os.path.isdir(os.path.join(SCRIPT_DIR, '../', project_name)):
    print """ERROR!
    You need to check and fix the os.environ['DJANGO_SETTINGS_MODULE']
    variable. It looks like the project path is wrong."""
    sys.exit(1)

if not os.path.isfile(os.path.join(SCRIPT_DIR, settings_name + ".py")):
    print """ERROR!
    You need to check and fix the os.environ['DJANGO_SETTINGS_MODULE']
    variable. It looks like the settings file does not exists"""
    sys.exit(1)

from django.conf import settings

# IMPORT SECTION --------------------------------------------------------------
try:
    from MYPROJECT.models import *
    # Here you can import other modules from your Django app
except ImportError:
    print """ERROR!
    It looks like you need to fix your module imports in the script.
    Please edit it and check the import section"""
    sys.exit(1)
# END IMPORT SECTION ----------------------------------------------------------

from django.core import serializers
from django.db.models import get_app, get_apps, get_models, get_model

def get_options():
    "defines options and arguments"
    usage = """usage: %prog [-d] [-f format] app1.model1 app2.model2...
    or
    %prog -a app1 app2
    """
    parser = OptionParser(usage)
    parser.add_option("-f", "--format", dest="format",
        action="store", type="string", default="json",
        help="format may be 'yaml' or 'json'. Default is 'json'")
    parser.add_option("-d", "--debug", dest="debug",
        action="store_true", default=False,
        help="prints debug information")
    parser.add_option("-a", "--all", dest="all",
        action="store_true", default=False,
        help='serialises every model available in the given applications'
    )
    return parser.parse_args()

def main():
    "main program"
    options, args = get_options()

    JSONSerializer = serializers.get_serializer("json")
    objects = []

    app_labels = []

    if options.all:
        if options.debug:
            print "All"
        for application in args:
            for model in get_models(get_app(application)):
                app_labels.append(tuple([application, model.__name__]))
    else:
        app_labels = [tuple(m.split('.', 1)) for m in args]

    if options.debug:
        print app_labels

    for app, model_name in app_labels:
        modele = get_model(app, model_name)
        if options.debug:
            print modele, app, model_name
        if modele:
            objects.extend(modele._default_manager.all())

    if options.format == 'json':
        data = serializers.serialize(options.format, objects,
            ensure_ascii=False, indent=4)
    else:
        data = serializers.serialize(options.format, objects, indent=4)

    print data

if __name__ == '__main__':

    main()

# EOF