Hello guys,
I’m trying to build the example app from elasticsearch dsl drf tutorial ( [https://django-elasticsearch-dsl-drf.readthedocs.io/en/0.20.8/quick_start.html#example-app] ),
but I’m facing an error when I migrate my models,
from django.utils.encoding import python_2_unicode_compatible
ImportError: cannot import name 'python_2_unicode_compatible' from 'django.utils.encoding'
Here are the models:
admin.py
from __future__ import unicode_literals
from django.utils.encoding import python_2_unicode_compatible
from django.contrib import admin
from .models import *
@admin.register(Book)
class BookAdmin(admin.ModelAdmin):
"""Book admin."""
list_display = ('title', 'isbn', 'price', 'publication_date')
search_fields = ('title',)
filter_horizontal = ('authors', 'tags',)
@admin.register(Author)
class AuthorAdmin(admin.ModelAdmin):
"""Author admin."""
list_display = ('name', 'email',)
search_fields = ('name',)
@admin.register(Publisher)
class PublisherAdmin(admin.ModelAdmin):
"""Publisher admin."""
list_display = ('name',)
search_fields = ('name',)
@admin.register(Tag)
class TagAdmin(admin.ModelAdmin):
"""Tag admin."""
list_display = ('title',)
search_fields = ('title',)
book.py
from __future__ import unicode_literals
from django.utils.encoding import python_2_unicode_compatible
import json
from django.conf import settings
from django.db import models
from django.utils.translation import ugettext, ugettext_lazy as _
# States indicate the publishing status of the book. Publishing might
# be in-progress, not yet published, published, rejected, etc.
BOOK_PUBLISHING_STATUS_PUBLISHED = 'published'
BOOK_PUBLISHING_STATUS_NOT_PUBLISHED = 'not_published'
BOOK_PUBLISHING_STATUS_IN_PROGRESS = 'in_progress'
BOOK_PUBLISHING_STATUS_CANCELLED = 'cancelled'
BOOK_PUBLISHING_STATUS_REJECTED = 'rejected'
BOOK_PUBLISHING_STATUS_CHOICES = (
(BOOK_PUBLISHING_STATUS_PUBLISHED, "Published"),
(BOOK_PUBLISHING_STATUS_NOT_PUBLISHED, "Not published"),
(BOOK_PUBLISHING_STATUS_IN_PROGRESS, "In progress"),
(BOOK_PUBLISHING_STATUS_CANCELLED, "Cancelled"),
(BOOK_PUBLISHING_STATUS_REJECTED, "Rejected"),
)
BOOK_PUBLISHING_STATUS_DEFAULT = BOOK_PUBLISHING_STATUS_PUBLISHED
@python_2_unicode_compatible
class Publisher(models.Model):
"""Publisher."""
name = models.CharField(max_length=30)
address = models.CharField(max_length=50)
city = models.CharField(max_length=60)
state_province = models.CharField(max_length=30)
country = models.CharField(max_length=50)
website = models.URLField()
latitude = models.DecimalField(null=True,
blank=True,
decimal_places=15,
max_digits=19,
default=0)
longitude = models.DecimalField(null=True,
blank=True,
decimal_places=15,
max_digits=19,
default=0)
class Meta(object):
"""Meta options."""
ordering = ["id"]
def __str__(self):
return self.name
@property
def location_field_indexing(self):
"""Location for indexing.
Used in Elasticsearch indexing/tests of `geo_distance` native filter.
"""
return {
'lat': self.latitude,
'lon': self.longitude,
}
@python_2_unicode_compatible
class Book(models.Model):
title = models.CharField(max_length=100)
description = models.TextField(null=True, blank=True)
summary = models.TextField(null=True, blank=True)
authors = models.ManyToManyField('books.Author', related_name='books')
publisher = models.ForeignKey(Publisher, related_name='books')
publication_date = models.DateField()
state = models.CharField(max_length=100,
choices=BOOK_PUBLISHING_STATUS_CHOICES,
default=BOOK_PUBLISHING_STATUS_DEFAULT)
isbn = models.CharField(max_length=100, unique=True)
price = models.DecimalField(max_digits=10, decimal_places=2)
pages = models.PositiveIntegerField(default=200)
stock_count = models.PositiveIntegerField(default=30)
tags = models.ManyToManyField('books.Tag',
related_name='books',
blank=True)
class Meta(object):
"""Meta options."""
ordering = ["isbn"]
def __str__(self):
return self.title
# The only publisher information we're going to need in our document
# is the publisher name. Since publisher isn't a required field,
# we define a properly on a model level to avoid indexing errors on
# non-existing relation.
@property
def publisher_indexing(self):
"""Publisher for indexing.
Used in Elasticsearch indexing.
"""
if self.publisher is not None:
return self.publisher.name
# As of tags, again, we only need a flat list of tag names, on which
# we can filter. Therefore, we define a properly on a model level,
# which will return a JSON dumped list of tags relevant to the
# current book model object.
@property
def tags_indexing(self):
"""Tags for indexing.
Used in Elasticsearch indexing.
"""
return [tag.title for tag in self.tags.all()]
Thank you for your help 
