Author: John Au-Yeung

Sometimes, we want to check if a user is in a certain group in Python Django.

In this article, we’ll look at how to check if a user is in a certain group in Python Django.

How to check if a user is in a certain group in Python Django?

To check if a user is in a certain group in Python Django, we can create a function.

For instance, we write

def is_member(user):
    return user.groups.filter(name='Member').exists()

to check if the user is in a group with name 'Member'.

We can also use the __in operator to check if a user is in multiple groups by writing

def is_in_multiple_groups(user):
    return user.groups.filter(name__in=['group1', 'group2']).exists()

Conclusion

To check if a user is in a certain group in Python Django, we can create a function.

Sometimes, we want to automate createsuperuser on Python Django.

In this article, we’ll look at how to automate createsuperuser on Python Django.

How to automate createsuperuser on Python Django?

To automate createsuperuser on Python Django, we can create a command.

For instance, we write

from django.contrib.auth.management.commands import createsuperuser
from django.core.management import CommandError


class Command(createsuperuser.Command):
    help = 'Crate a superuser, and allow password to be provided'

    def add_arguments(self, parser):
        super(Command, self).add_arguments(parser)
        parser.add_argument(
            '--password', dest='password', default=None,
            help='Specifies the password for the superuser.',
        )

    def handle(self, *args, **options):
        password = options.get('password')
        username = options.get('username')
        database = options.get('database')

        if password and not username:
            raise CommandError("--username is required if specifying --password")

        super(Command, self).handle(*args, **options)

        if password:
            user = self.UserModel._default_manager.db_manager(database).get(username=username)
            user.set_password(password)
            user.save()

to create the Command class that’s a subclass of the createsuperuser.Command class.

In it, we add the password argument within the add_arguments method.

And then in the handle method, we get the command line arguments from options.get.

Next, we add some validation with if statements and call save is the password and username are set.

Conclusion

To automate createsuperuser on Python Django, we can create a command.

Sometimes, we want to change Python Django settings at runtime.

In this article, we’ll look at how to change Python Django settings at runtime.

How to change Python Django settings at runtime?

To change Python Django settings at runtime, we can set the conf.settings dictionary.

For instance, we write

import django.conf as conf

conf.settings.DATABASES['default']['NAME'] = 'abc'

to set the conf.settings.DATABASES['default']['NAME'] field to a value in the entry point of our app.

Conclusion

To change Python Django settings at runtime, we can set the conf.settings dictionary.

Sometimes, we want to do a left join with the Python Django ORM.

In this article, we’ll look at how to do a left join with the Python Django ORM.

How to do a left join with the Python Django ORM?

To do a left join with the Python Django ORM, we can call filter with the related table field’s is_null argument set to True.

For instance, we write

Department.objects.filter(departmentvolunteer__department__isnull=True)

to call filter with the departmentvolunteer__department__isnull set to True to do a left join on the departmentvolunteer table by making the foreign key optional.

Conclusion

To do a left join with the Python Django ORM, we can call filter with the related table field’s is_null argument set to True.

Sometimes, we want to store a dictionary on a Python Django Model.

In this article, we’ll look at how to store a dictionary on a Python Django Model.

How to store a dictionary on a Python Django Model?

To store a dictionary on a Python Django Model, we can create a JSONField with the jsonfield package.

To install it, we run

pip install jsonfield

to install it.

Then we write

from django.db import models
from jsonfield import JSONField

class MyModel(models.Model):
    json = JSONField()

to create the json JSONField in MyModel to create the JSON field.

Conclusion

To store a dictionary on a Python Django Model, we can create a JSONField with the jsonfield package.