Django 1.0 breaks compatibility with 0.96 in some areas.
This guide will help you port 0.96 projects and apps to 1.0. The first part of this document includes the common changes needed to run with 1.0. If after going through the first part your code still breaks, check the section Less-common Changes for a list of a bunch of less-common compatibility issues.
See also
The 1.0 release notes. That document explains the new features in 1.0 more deeply; the porting guide is more concerned with helping you quickly update your code.
This section describes the changes between 0.96 and 1.0 that most users will need to make.
Change string literals ('foo') into Unicode literals (u'foo'). Django now uses Unicode strings throughout. In most places, raw strings will continue to work, but updating to use Unicode literals will prevent some obscure problems.
See Unicode data for full details.
Common changes to your models file:
Rename your maxlength argument to max_length (this was changed to be consistent with form fields):
Replace your model’s __str__ function with a __unicode__ method, and make sure you use Unicode (u'foo') in that method.
Remove the prepopulated_from argument on model fields. It’s no longer valid and has been moved to the ModelAdmin class in admin.py. See the admin, below, for more details about changes to the admin.
Remove the core argument from your model fields. It is no longer necessary, since the equivalent functionality (part of inline editing) is handled differently by the admin interface now. You don’t have to worry about inline editing until you get to the admin section, below. For now, remove all references to core.
Remove all your inner class Admin declarations from your models. They won’t break anything if you leave them, but they also won’t do anything. To register apps with the admin you’ll move those declarations to an admin.py file; see the admin below for more details.
See also
A contributor to djangosnippets has written a script that’ll scan your models.py and generate a corresponding admin.py.
Below is an example models.py file with all the changes you’ll need to make:
Old (0.96) models.py:
class Author(models.Model):
first_name = models.CharField(maxlength=30)
last_name = models.CharField(maxlength=30)
slug = models.CharField(maxlength=60, prepopulate_from=('first_name', 'last_name'))
class Admin:
list_display = ['first_name', 'last_name']
def __str__(self):
return '%s %s' % (self.first_name, self.last_name)
New (1.0) models.py:
class Author(models.Model):
first_name = models.CharField(max_length=30)
last_name = models.CharField(max_length=30)
slug = models.CharField(max_length=60)
def __unicode__(self):
return u'%s %s' % (self.first_name, self.last_name)
New (1.0) admin.py:
from django.contrib import admin
from models import Author
class AuthorAdmin(admin.ModelAdmin):
list_display = ['first_name', 'last_name']
prepopulated_fields = {
'slug': ('first_name', 'last_name')
}
admin.site.register(Author, AuthorAdmin)
One of the biggest changes in 1.0 is the new admin. The Django administrative interface (django.contrib.admin) has been completely refactored; admin definitions are now completely decoupled from model definitions, the framework has been rewritten to use Django’s new form-handling library and redesigned with extensibility and customization in mind.
Practically, this means you’ll need to rewrite all of your class Admin declarations. You’ve already seen in models above how to replace your class Admin with a admin.site.register() call in an admin.py file. Below are some more details on how to rewrite that Admin declaration into the new syntax.
The new edit_inline options have all been moved to admin.py. Here’s an example:
Old (0.96):
class Parent(models.Model):
...
class Child(models.Model):
parent = models.ForeignKey(Parent, edit_inline=models.STACKED, num_in_admin=3)
New (1.0):
class ChildInline(admin.StackedInline):
model = Child
extra = 3
class ParentAdmin(admin.ModelAdmin):
model = Parent
inlines = [ChildInline]
admin.site.register(Parent, ParentAdmin)
See InlineModelAdmin objects for more details.
The old fields syntax was quite confusing, and has been simplified. The old syntax still works, but you’ll need to use fieldsets instead.
Old (0.96):
class ModelOne(models.Model):
...
class Admin:
fields = (
(None, {'fields': ('foo','bar')}),
)
class ModelTwo(models.Model):
...
class Admin:
fields = (
('group1', {'fields': ('foo','bar'), 'classes': 'collapse'}),
('group2', {'fields': ('spam','eggs'), 'classes': 'collapse wide'}),
)
New (1.0):
class ModelOneAdmin(admin.ModelAdmin):
fields = ('foo', 'bar')
class ModelTwoAdmin(admin.ModelAdmin):
fieldsets = (
('group1', {'fields': ('foo','bar'), 'classes': 'collapse'}),
('group2', {'fields': ('spam','eggs'), 'classes': 'collapse wide'}),
)
See also
If you’re using the admin site, you need to update your root urls.py.
Old (0.96) urls.py:
from django.conf.urls.defaults import *
urlpatterns = patterns('',
(r'^admin/', include('django.contrib.admin.urls')),
# ... the rest of your URLs here ...
)
New (1.0) urls.py:
from django.conf.urls.defaults import *
# The next two lines enable the admin and load each admin.py file:
from django.contrib import admin
admin.autodiscover()
urlpatterns = patterns('',
(r'^admin/(.*)', admin.site.root),
# ... the rest of your URLs here ...
)
Replace django.newforms with django.forms – Django 1.0 renamed the newforms module (introduced in 0.96) to plain old forms. The oldforms module was also removed.
If you’re already using the newforms library, and you used our recommended import statement syntax, all you have to do is change your import statements.
Old:
from django import newforms as forms
New:
from django import forms
If you’re using the old forms system (formerly known as django.forms and django.oldforms), you’ll have to rewrite your forms. A good place to start is the forms documentation
Replace use of uploaded files – that is, entries in request.FILES – as simple dictionaries with the new UploadedFile. The old dictionary syntax no longer works.
Thus, in a view like:
def my_view(request):
f = request.FILES['file_field_name']
...
...you’d need to make the following changes:
| Old (0.96) | New (1.0) |
|---|---|
| f['content'] | f.read() |
| f['filename'] | f.name |
| f['content-type'] | f.content_type |
The internal implementation of django.db.models.FileField have changed. A visible result of this is that the way you access special attributes (URL, filename, image size, etc) of these model fields has changed. You will need to make the following changes, assuming your model’s FileField is called myfile:
| Old (0.96) | New (1.0) |
|---|---|
| myfile.get_content_filename() | myfile.content.path |
| myfile.get_content_url() | myfile.content.url |
| myfile.get_content_size() | myfile.content.size |
| myfile.save_content_file() | myfile.content.save() |
| myfile.get_content_width() | myfile.content.width |
| myfile.get_content_height() | myfile.content.height |
Note that the width and height attributes only make sense for ImageField fields. More details can be found in the model API documentation.
The ObjectPaginator in 0.96 has been removed and replaced with an improved version, django.core.paginator.Paginator.
By default, the template system now automatically HTML-escapes the output of every variable. To learn more, see Automatic HTML escaping.
To disable auto-escaping for an individual variable, use the safe filter:
This will be escaped: {{ data }}
This will not be escaped: {{ data|safe }}
To disable auto-escaping for an entire template, wrap the template (or just a particular section of the template) in the autoescape tag:
{% autoescape off %}
... unescaped template content here ...
{% endautoescape %}
The following changes are smaller, more localized changes. They should only affect more advanced users, but it’s probably worth reading through the list and checking your code for these things.
Here’s quick summary of the code changes you’ll need to make:
| Old (0.96) | New (1.0) |
|---|---|
| def callback(sender) | def callback(sender, **kwargs) |
| sig = object() | sig = django.dispatch.Signal() |
| dispatcher.connect(callback, sig) | sig.connect(callback) |
| dispatcher.send(sig, sender) | sig.send(sender) |
| dispatcher.connect(callback, sig, sender=Any) | sig.connect(callback, sender=None) |
If you were using Django 0.96’s django.contrib.comments app, you’ll need to upgrade to the new comments app introduced in 1.0. See the upgrade guide for details.
django.contrib.localflavor.usa has been renamed to django.contrib.localflavor.us. This change was made to match the naming scheme of other local flavors. To migrate your code, all you need to do is change the imports.
SessionBase.get_new_session_key() has been renamed to _get_new_session_key(). get_new_session_object() no longer exists.
Previously, loading a row automatically ran the model’s save() method. This is no longer the case, so any fields (for example: timestamps) that were auto-populated by a save() now need explicit values in any fixture.
The old EnvironmentError has split into an ImportError when Django fails to find the settings module and a RuntimeError when you try to reconfigure settings after having already used them
The LOGIN_URL constant moved from django.contrib.auth into the settings module. Instead of using from django.contrib.auth import LOGIN_URL refer to settings.LOGIN_URL.
In 0.96, if a URL didn’t end in a slash or have a period in the final component of its path, and APPEND_SLASH was True, Django would redirect to the same URL, but with a slash appended to the end. Now, Django checks to see whether the pattern without the trailing slash would be matched by something in your URL patterns. If so, no redirection takes place, because it is assumed you deliberately wanted to catch that pattern.
For most people, this won’t require any changes. Some people, though, have URL patterns that look like this:
r'/some_prefix/(.*)$'
Previously, those patterns would have been redirected to have a trailing slash. If you always want a slash on such URLs, rewrite the pattern as:
r'/some_prefix/(.*/)$'
Managers now return a MultipleObjectsReturned exception instead of AssertionError:
Old (0.96):
try:
Model.objects.get(...)
except AssertionError:
handle_the_error()
New (1.0):
try:
Model.objects.get(...)
except Model.MultipleObjectsReturned:
handle_the_error()
The LazyDate helper class no longer exists.
Default field values and query arguments can both be callable objects, so instances of LazyDate can be replaced with a reference to datetime.datetime.now:
Old (0.96):
class Article(models.Model):
title = models.CharField(maxlength=100)
published = models.DateField(default=LazyDate())
New (1.0):
import datetime
class Article(models.Model):
title = models.CharField(max_length=100)
published = models.DateField(default=datetime.datetime.now)
Old (0.96):
class MyModel(models.Model):
field_name = models.FloatField(max_digits=10, decimal_places=3)
...
New (1.0):
class MyModel(models.Model):
field_name = models.DecimalField(max_digits=10, decimal_places=3)
...
If you forget to make this change, you will see errors about FloatField not taking a max_digits attribute in __init__, because the new FloatField takes no precision-related arguments.
If you’re using MySQL or PostgreSQL, no further changes are needed. The database column types for DecimalField are the same as for the old FloatField.
If you’re using SQLite, you need to force the database to view the appropriate columns as decimal types, rather than floats. To do this, you’ll need to reload your data. Do this after you have made the change to using DecimalField in your code and updated the Django code.
Warning
Back up your database first!
For SQLite, this means making a copy of the single file that stores the database (the name of that file is the DATABASE_NAME in your settings.py file).
To upgrade each application to use a DecimalField, you can do the following, replacing <app> in the code below with each app’s name:
$ ./manage.py dumpdata --format=xml <app> > data-dump.xml
$ ./manage.py reset <app>
$ ./manage.py loaddata data-dump.xml
Notes:
If something goes wrong in the above process, just copy your backed up database file over the original file and start again.
Previously, a GET request was used. The old behavior meant that state (the locale used to display the site) could be changed by a GET request, which is against the HTTP specification’s recommendations. Code calling this view must ensure that a POST request is now made, instead of a GET. This means you can no longer use a link to access the view, but must use a form submission of some kind (e.g. a button).
_() (the callable object whose name is a single underscore) is no longer monkeypatched into builtins – that is, it’s no longer available magically in every module.
If you were previously relying on _() always being present, you should now explicitly import ugettext or ugettext_lazy, if appropriate, and alias it to _ yourself:
from django.utils.translation import ugettext as _
HttpRequest objects no longer directly support dictionary-style access; previously, both GET and POST data were directly available on the HttpRequest object (e.g., you could check for a piece of form data by using if 'some_form_key' in request or by reading request['some_form_key']. This is no longer supported; if you need access to the combined GET and POST data, use request.REQUEST instead.
It is strongly suggested, however, that you always explicitly look in the appropriate dictionary for the type of request you expect to receive (request.GET or request.POST); relying on the combined request.REQUEST dictionary can mask the origin of incoming data.
django.http.HttpResponse.headers has been renamed to _headers and HttpResponse now supports containment checking directly. So use if header in response: instead of if header in response.headers:.
The generic relation classes – GenericForeignKey and GenericRelation – have moved into the django.contrib.contenttypes module.
Old (0.96):
from django.test import Client
c = Client()
c.login('/path/to/login','myuser','mypassword')
New (1.0):
# ... same as above, but then:
c.login(username='myuser', password='mypassword')
django.core.management has been greatly refactored.
Calls to management services in your code now need to use call_command. For example, if you have some test code that calls flush and load_data:
from django.core import management
management.flush(verbosity=0, interactive=False)
management.load_data(['test_data'], verbosity=0)
...you’ll need to change this code to read:
from django.core import management
management.call_command('flush', verbosity=0, interactive=False)
management.call_command('loaddata', 'test_data', verbosity=0)
django-admin.py and manage.py now require subcommands to precede options. So:
$ django-admin.py --settings=foo.bar runserver
...no longer works and should be changed to:
$ django-admin.py runserver --settings=foo.bar
The __init__() method of the syndication framework’s Feed class now takes an HttpRequest object as its second parameter, instead of the feed’s URL. This allows the syndication framework to work without requiring the sites framework. This only affects code that subclasses Feed and overrides the __init__() method, and code that calls Feed.__init__() directly.
django.newforms.forms.SortedDictFromList was removed. django.utils.datastructures.SortedDict can now be instantiated with a sequence of tuples.
To update your code:
Almost all of the database backend-level functions have been renamed and/or relocated. None of these were documented, but you’ll need to change your code if you’re using any of these functions, all of which are in django.db:
| Old (0.96) | New (1.0) |
|---|---|
| backend.get_autoinc_sql | connection.ops.autoinc_sql |
| backend.get_date_extract_sql | connection.ops.date_extract_sql |
| backend.get_date_trunc_sql | connection.ops.date_trunc_sql |
| backend.get_datetime_cast_sql | connection.ops.datetime_cast_sql |
| backend.get_deferrable_sql | connection.ops.deferrable_sql |
| backend.get_drop_foreignkey_sql | connection.ops.drop_foreignkey_sql |
| backend.get_fulltext_search_sql | connection.ops.fulltext_search_sql |
| backend.get_last_insert_id | connection.ops.last_insert_id |
| backend.get_limit_offset_sql | connection.ops.limit_offset_sql |
| backend.get_max_name_length | connection.ops.max_name_length |
| backend.get_pk_default_value | connection.ops.pk_default_value |
| backend.get_random_function_sql | connection.ops.random_function_sql |
| backend.get_sql_flush | connection.ops.sql_flush |
| backend.get_sql_sequence_reset | connection.ops.sequence_reset_sql |
| backend.get_start_transaction_sql | connection.ops.start_transaction_sql |
| backend.get_tablespace_sql | connection.ops.tablespace_sql |
| backend.quote_name | connection.ops.quote_name |
| backend.get_query_set_class | connection.ops.query_set_class |
| backend.get_field_cast_sql | connection.ops.field_cast_sql |
| backend.get_drop_sequence | connection.ops.drop_sequence_sql |
| backend.OPERATOR_MAPPING | connection.operators |
| backend.allows_group_by_ordinal | connection.features.allows_group_by_ordinal |
| backend.allows_unique_and_pk | connection.features.allows_unique_and_pk |
| backend.autoindexes_primary_keys | connection.features.autoindexes_primary_keys |
| backend.needs_datetime_string_cast | connection.features.needs_datetime_string_cast |
| backend.needs_upper_for_iops | connection.features.needs_upper_for_iops |
| backend.supports_constraints | connection.features.supports_constraints |
| backend.supports_tablespaces | connection.features.supports_tablespaces |
| backend.uses_case_insensitive_names | connection.features.uses_case_insensitive_names |
| backend.uses_custom_queryset | connection.features.uses_custom_queryset |
Dec 23, 2012