Some Django model mixins

mixins.py

# Copyright (c) 2012, Vehbi Sinan Tunalioglu <vst@vsthost.com>
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from django.db import models
from echelon.fields import CurrentUserField


class CreateMixin(models.Model):
    """
    Provides a mixin for annotating a DB object with timestamp and
    user information of creation.
    """

    created_at = models.DateTimeField(auto_now_add=True)
    """
    Defines the date and time when the object is created at.
    """

    created_by = CurrentUserField(add_only=True,
                                  related_name="created_%(class)s")
    """
    Relates to the user whom the object is created by.
    """

    class Meta:
        abstract = True


class ModifyMixin(models.Model):
    """
    Provides a mixin for annotating a DB object with timestamp and
    user information of modification.
    """

    modified_at = models.DateTimeField(auto_now_add=True)
    """
    Defines the date and time when the object is modified at.
    """

    modified_by = CurrentUserField(related_name="modified_%(class)s")
    """
    Relates to the user whom the object is modified by.
    """

    class Meta:
        abstract = True

hello django