django-duplicator

A lightweight mixin for Django Admin that adds object duplication, both in bulk (an admin action) and for single objects (a "Duplicate and continue editing" button on the change form).

• Single duplication: a "Duplicate and continue editing" button on the change form opens the new copy.
• Bulk duplication: an admin action duplicates the selected objects from the changelist, all or nothing.
• Data control: exclude fields from duplication, such as unique fields or timestamps.
• Safe by default: duplicating needs a POST and the right permissions, and database errors are shown as messages instead of crashing the admin.

Installation

pip install django-duplicator

Requires Python 3.10+ and Django 4.2+ (tested on 4.2, 5.2, 6.0 and 6.1).

Add duplicator to your INSTALLED_APPS:

# settings.py
INSTALLED_APPS = [
    # ...
    "django.contrib.admin",
    # ...
    "duplicator",
]

Usage

1. Model

Inherit from DuplicatorMixin to make a model duplicatable:

# models.py
from django.db import models
from duplicator import DuplicatorMixin


class Customer(DuplicatorMixin, models.Model):
    name = models.CharField(max_length=255)

    def __str__(self):
        return self.name

2. Admin

Inherit from DuplicatorAdminMixin to get both the change form button and the bulk action:

# admin.py
from django.contrib import admin
from duplicator import DuplicatorAdminMixin
from .models import Customer


@admin.register(Customer)
class CustomerAdmin(DuplicatorAdminMixin, admin.ModelAdmin):
    list_display = ("name", "id")

A user needs the add permission, plus view or change permission on the object, to duplicate it.

What gets copied

• Every concrete field except primary keys, so the copy is a new row. With multi-table inheritance, the parent rows are new as well; the original is never modified.
• Foreign keys point to the same related objects.
• Many-to-many relations, except those with a custom through model (they can carry extra data, so copying them is up to you).
• A text field called name gets a (Copy) suffix, shortened if needed to fit its max_length. Empty names are left as they are.

The copy is made from the saved object: unsaved edits on the change form are not included.

Customization

Excluding fields

List fields that must not be copied in DUPLICATOR_EXCLUDE_FIELDS. They get their default value on the copy, like on a new record. This works for many-to-many fields too.

# models.py
from duplicator import DuplicatorMixin


class Product(DuplicatorMixin, models.Model):
    DUPLICATOR_EXCLUDE_FIELDS = [
        "sku",  # unique
        "created_at",
        "last_modified",
    ]

    name = models.CharField(max_length=255)
    sku = models.CharField(max_length=100, unique=True)
    created_at = models.DateTimeField(auto_now_add=True)

If a copy breaks a database constraint, for example a unique field that is not excluded, the admin shows the error and nothing is duplicated.

Overriding values

clone() accepts field values for the copy:

copy = product.clone(name="Product B", sku="B-001")

Customizing clone()

Override clone() to adjust the copy. With commit=False, save the copy yourself and then copy the many-to-many relations:

class Product(DuplicatorMixin, models.Model):
    def clone(self, commit=True, **kwargs):
        copy = super().clone(commit=False, **kwargs)
        copy.sku = f"{self.sku}-COPY"
        if commit:
            copy.save()
            self.copy_many_to_many(copy)
        return copy

Feature demonstration

A. Bulk duplication (admin action)

The duplication option appears in the Actions dropdown menu on the changelist page.

B. Single duplication (change form button)

The "Duplicate and continue editing" button is placed on the object detail page.

Upgrading from 0.1

• The duplicate view only accepts POST. The change form button already submits a POST; if you linked to <object_id>/duplicate/ yourself, submit a form instead of following a link.
• Users without permission get a 403 instead of a server error, and they need view or change permission on the object as well as the add permission.
• Many-to-many relations are now copied. Add them to DUPLICATOR_EXCLUDE_FIELDS to keep the old behaviour.
• Python 3.8 and 3.9 are no longer supported.
• Fixed: a model without its own class Meta became abstract (no table) because of the mixin.
• Fixed: duplicating a multi-table inheritance child overwrote the original's parent row.

Development

make install   # poetry install
make test      # tests with coverage
make format    # black

Help & Bugs

If you find a bug or have a feature suggestion, please open an issue or submit a pull request.

License

django-duplicator is released under MIT. See LICENSE for more details.