픽스처Link to this heading#

How to produce a fixtureLink to this heading#

Fixtures can be generated by manage.py dumpdata. It’s also possible to generate custom fixtures by directly using serialization tools or even by handwriting them.

How to use a fixtureLink to this heading#

Fixtures can be used to pre-populate the database with data for tests:

class MyTestCase(TestCase):
    fixtures = ["fixture-label"]

or to provide some initial data using the loaddata command:

django-admin loaddata <fixture label>

How fixtures are discoveredLink to this heading#

Django will search in these locations for fixtures:

1. In the fixtures directory of every installed application

2. In any directory listed in the FIXTURE_DIRS setting

3. In the literal path named by the fixture

Django will load any and all fixtures it finds in these locations that match the provided fixture names. If the named fixture has a file extension, only fixtures of that type will be loaded. For example:

django-admin loaddata mydata.json

would only load JSON fixtures called mydata. The fixture extension must correspond to the registered name of a serializer (e.g., json or xml).

If you omit the extensions, Django will search all available fixture types for a matching fixture. For example:

django-admin loaddata mydata

would look for any fixture of any fixture type called mydata. If a fixture directory contained mydata.json, that fixture would be loaded as a JSON fixture.

The fixtures that are named can include directory components. These directories will be included in the search path. For example:

django-admin loaddata foo/bar/mydata.json

would search <app_label>/fixtures/foo/bar/mydata.json for each installed application, <dirname>/foo/bar/mydata.json for each directory in FIXTURE_DIRS, and the literal path foo/bar/mydata.json.

django-admin loaddata mammals birds insects

class AnimalTestCase(TestCase):
    fixtures = ["mammals", "birds", "insects"]

How fixtures are saved to the databaseLink to this heading#

When fixture files are processed, the data is saved to the database as is. Model defined save() methods are not called, and any pre_save or post_save signals will be called with raw=True since the instance only contains attributes that are local to the model. You may, for example, want to disable handlers that access related fields that aren’t present during fixture loading and would otherwise raise an exception:

from django.db.models.signals import post_save
from .models import MyModel


def my_handler(**kwargs):
    # disable the handler during fixture loading
    if kwargs["raw"]:
        return
    ...


post_save.connect(my_handler, sender=MyModel)

You could also write a decorator to encapsulate this logic:

from functools import wraps


def disable_for_loaddata(signal_handler):
    """
    Decorator that turns off signal handlers when loading fixture data.
    """

    @wraps(signal_handler)
    def wrapper(*args, **kwargs):
        if kwargs["raw"]:
            return
        signal_handler(*args, **kwargs)

    return wrapper


@disable_for_loaddata
def my_handler(**kwargs): ...

Just be aware that this logic will disable the signals whenever fixtures are deserialized, not just during loaddata.

Compressed fixturesLink to this heading#

Fixtures may be compressed in zip, gz, bz2, lzma, or xz format. For example:

django-admin loaddata mydata.json

would look for any of mydata.json, mydata.json.zip, mydata.json.gz, mydata.json.bz2, mydata.json.lzma, or mydata.json.xz. The first file contained within a compressed archive is used.

Note that if two fixtures with the same name but different fixture type are discovered (for example, if mydata.json and mydata.xml.gz were found in the same fixture directory), fixture installation will be aborted, and any data installed in the call to loaddata will be removed from the database.

Database-specific fixturesLink to this heading#

If you’re in a multi-database setup, you might have fixture data that you want to load onto one database, but not onto another. In this situation, you can add a database identifier into the names of your fixtures.

For example, if your DATABASES setting has a users database defined, name the fixture mydata.users.json or mydata.users.json.gz and the fixture will only be loaded when you specify you want to load data into the users database.