Getting started

Test data

There are test data files which can be used for importing in the test/core/exports directory.

The test models

For example purposes, we’ll use a simplified book app. Here is our models.py:

# app/models.py

class Author(models.Model):
    name = models.CharField(max_length=100)

    def __str__(self):
        return self.name


class Category(models.Model):
    name = models.CharField(max_length=100)

    def __str__(self):
        return self.name


class Book(models.Model):
    name = models.CharField('Book name', max_length=100)
    author = models.ForeignKey(Author, blank=True, null=True)
    author_email = models.EmailField('Author email', max_length=75, blank=True)
    imported = models.BooleanField(default=False)
    published = models.DateField('Published', blank=True, null=True)
    price = models.DecimalField(max_digits=10, decimal_places=2, null=True, blank=True)
    categories = models.ManyToManyField(Category, blank=True)

    def __str__(self):
        return self.name

Creating import-export resource

To integrate django-import-export with our Book model, we will create a ModelResource class in admin.py that will describe how this resource can be imported or exported:

# app/admin.py

from import_export import resources
from core.models import Book

class BookResource(resources.ModelResource):

    class Meta:
        model = Book

Exporting data

Now that we have defined a ModelResource class, we can export books:

>>> from app.admin import BookResource
>>> dataset = BookResource().export()
>>> print(dataset.csv)
id,name,author,author_email,imported,published,price,categories
2,Some book,1,,0,2012-12-05,8.85,1

Customize resource options

By default ModelResource introspects model fields and creates Field-attributes with an appropriate Widget for each field.

To affect which model fields will be included in an import-export resource, use the fields option to whitelist fields:

class BookResource(resources.ModelResource):

    class Meta:
        model = Book
        fields = ('id', 'name', 'price',)

Or the exclude option to blacklist fields:

class BookResource(resources.ModelResource):

    class Meta:
        model = Book
        exclude = ('imported', )

An explicit order for exporting fields can be set using the export_order option:

class BookResource(resources.ModelResource):

    class Meta:
        model = Book
        fields = ('id', 'name', 'author', 'price',)
        export_order = ('id', 'price', 'author', 'name')

The default field for object identification is id, you can optionally set which fields are used as the id when importing:

class BookResource(resources.ModelResource):

    class Meta:
        model = Book
        import_id_fields = ('isbn',)
        fields = ('isbn', 'name', 'author', 'price',)

When defining ModelResource fields it is possible to follow model relationships:

class BookResource(resources.ModelResource):

    class Meta:
        model = Book
        fields = ('author__name',)

Note

Following relationship fields sets field as readonly, meaning this field will be skipped when importing data.

By default all records will be imported, even if no changes are detected. This can be changed setting the skip_unchanged option. Also, the report_skipped option controls whether skipped records appear in the import Result object, and if using the admin whether skipped records will show in the import preview page:

class BookResource(resources.ModelResource):

    class Meta:
        model = Book
        skip_unchanged = True
        report_skipped = False
        fields = ('id', 'name', 'price',)

To further customize the resources, you might like to consider overriding the following ImportMixin methods: get_resource_kwargs(), get_resource_classes(), get_export_resource_kwargs(),

See also

Resources

Declaring fields

It is possible to override a resource field to change some of its options:

from import_export.fields import Field

class BookResource(resources.ModelResource):
    published = Field(attribute='published', column_name='published_date')

    class Meta:
        model = Book

Other fields that don’t exist in the target model may be added:

from import_export.fields import Field

class BookResource(resources.ModelResource):
    myfield = Field(column_name='myfield')

    class Meta:
        model = Book

See also

Fields
Available field types and options.

Advanced data manipulation on export

Not all data can be easily extracted from an object/model attribute. In order to turn complicated data model into a (generally simpler) processed data structure on export, dehydrate_<fieldname> method should be defined:

from import_export.fields import Field

class BookResource(resources.ModelResource):
    full_title = Field()

    class Meta:
        model = Book

    def dehydrate_full_title(self, book):
        book_name = getattr(book, "name", "unknown")
        author_name = getattr(book.author, "name", "unknown")
        return '%s by %s' % (book_name, author_name)

In this case, the export looks like this:

>>> from app.admin import BookResource
>>> dataset = BookResource().export()
>>> print(dataset.csv)
full_title,id,name,author,author_email,imported,published,price,categories
Some book by 1,2,Some book,1,,0,2012-12-05,8.85,1

Customize widgets

A ModelResource creates a field with a default widget for a given field type. If the widget should be initialized with different arguments, set the widgets dict.

In this example widget, the published field is overridden to use a different date format. This format will be used both for importing and exporting resource.

class BookResource(resources.ModelResource):

    class Meta:
        model = Book
        widgets = {
                'published': {'format': '%d.%m.%Y'},
                }

See also

Widgets
available widget types and options.

Django Natural Keys

The ForeignKeyWidget also supports using Django’s natural key functions. A manager class with the get_by_natural_key function is required for importing foreign key relationships by the field model’s natural key, and the model must have a natural_key function that can be serialized as a JSON list in order to export data.

The primary utility for natural key functionality is to enable exporting data that can be imported into other Django environments with different numerical primary key sequences. The natural key functionality enables handling more complex data than specifying either a single field or the PK.

The example below illustrates how to create a field on the BookResource that imports and exports its author relationships using the natural key functions on the Author model and modelmanager.

The resource _meta option use_natural_foreign_keys enables this setting for all Models that support it.

from import_export.fields import Field
from import_export.widgets import ForeignKeyWidget

class AuthorManager(models.Manager):

    def get_by_natural_key(self, name):
        return self.get(name=name)

class Author(models.Model):

    objects = AuthorManager()

    name = models.CharField(max_length=100)
    birthday = models.DateTimeField(auto_now_add=True)

    def natural_key(self):
        return (self.name,)

# Only the author field uses natural foreign keys.
class BookResource(resources.ModelResource):

    author = Field(
        column_name = "author",
        attribute = "author",
        widget = ForeignKeyWidget(Author, use_natural_foreign_keys=True)
    )

    class Meta:
        model = Book

# All widgets with foreign key functions use them.
class BookResource(resources.ModelResource):

    class Meta:
        model = Book
        use_natural_foreign_keys = True

Read more at Django Serialization

Importing data

Let’s import some data!

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>>> import tablib
>>> from import_export import resources
>>> from core.models import Book
>>> book_resource = resources.modelresource_factory(model=Book)()
>>> dataset = tablib.Dataset(['', 'New book'], headers=['id', 'name'])
>>> result = book_resource.import_data(dataset, dry_run=True)
>>> print(result.has_errors())
False
>>> result = book_resource.import_data(dataset, dry_run=False)

In the fourth line we use modelresource_factory() to create a default ModelResource. The ModelResource class created this way is equal to the one shown in the example in section Creating import-export resource.

In fifth line a Dataset with columns id and name, and one book entry, are created. A field for a primary key field (in this case, id) always needs to be present.

In the rest of the code we first pretend to import data using import_data() and dry_run set, then check for any errors and actually import data this time.

See also

Import data workflow
for a detailed description of the import workflow and its customization options.

Deleting data

To delete objects during import, implement the for_delete() method on your Resource class.

The following is an example resource which expects a delete field in the dataset. An import using this resource will delete model instances for rows that have their column delete set to 1:

class BookResource(resources.ModelResource):
    delete = fields.Field(widget=widgets.BooleanWidget())

    def for_delete(self, row, instance):
        return self.fields['delete'].clean(row)

    class Meta:
        model = Book

Signals

To hook in the import export workflow, you can connect to post_import, post_export signals:

from django.dispatch import receiver
from import_export.signals import post_import, post_export

@receiver(post_import, dispatch_uid='balabala...')
def _post_import(model, **kwargs):
    # model is the actual model instance which after import
    pass

@receiver(post_export, dispatch_uid='balabala...')
def _post_export(model, **kwargs):
    # model is the actual model instance which after export
    pass

Admin integration

Exporting

Exporting via list filters

Admin integration is achieved by subclassing ImportExportModelAdmin or one of the available mixins (ImportMixin, ExportMixin, ImportExportMixin):

# app/admin.py
from .models import Book
from import_export.admin import ImportExportModelAdmin

class BookAdmin(ImportExportModelAdmin):
    resource_classes = [BookResource]

admin.site.register(Book, BookAdmin)
_images/django-import-export-change.png

A screenshot of the change view with Import and Export buttons.

_images/django-import-export-import.png

A screenshot of the import view.

_images/django-import-export-import-confirm.png

A screenshot of the confirm import view.

Warning

The resource_class parameter was deprecated in django-import-export 3.0. Assign list or tuple with Resource(s) to resource_classes parameter now.

Exporting via admin action

Another approach to exporting data is by subclassing ImportExportActionModelAdmin which implements export as an admin action. As a result it’s possible to export a list of objects selected on the change list page:

# app/admin.py
from import_export.admin import ImportExportActionModelAdmin

class BookAdmin(ImportExportActionModelAdmin):
    pass
_images/django-import-export-action.png

A screenshot of the change view with Import and Export as an admin action.

Note that to use the ExportMixin or ExportActionMixin, you must declare this mixin before admin.ModelAdmin:

# app/admin.py
from django.contrib import admin
from import_export.admin import ExportActionMixin

class BookAdmin(ExportActionMixin, admin.ModelAdmin):
    pass

Note that ExportActionMixin is declared first in the example above!

Importing

It is also possible to enable data import via standard Django admin interface. To do this subclass ImportExportModelAdmin or use one of the available mixins, i.e. ImportMixin, or ImportExportMixin. Customizations are, of course, possible.

Customize admin import forms

It is possible to modify default import forms used in the model admin. For example, to add an additional field in the import form, subclass and extend the ImportForm (note that you may want to also consider ConfirmImportForm as importing is a two-step process).

To use your customized form(s), change the respective attributes on your ModelAdmin class:

For example, imagine you want to import books for a specific author. You can extend the import forms to include author field to select the author from.

Customize forms:

from django import forms

class CustomImportForm(ImportForm):
    author = forms.ModelChoiceField(
        queryset=Author.objects.all(),
        required=True)

class CustomConfirmImportForm(ConfirmImportForm):
    author = forms.ModelChoiceField(
        queryset=Author.objects.all(),
        required=True)

Customize ModelAdmin:

class CustomBookAdmin(ImportMixin, admin.ModelAdmin):
    resource_classes = [BookResource]
    import_form_class = CustomImportForm
    confirm_form_class = CustomConfirmImportForm

    def get_confirm_form_initial(self, request, import_form):
        initial = super().get_confirm_form_initial(request, import_form)
        # Pass on the `author` value from the import form to
        # the confirm form (if provided)
        if import_form:
            initial['author'] = import_form.cleaned_data['author']
        return initial

admin.site.register(Book, CustomBookAdmin)

To further customize the import forms, you might like to consider overriding the following ImportMixin methods: get_import_form_class(), get_import_form_kwargs(), get_import_form_initial(), get_confirm_form_class(), get_confirm_form_kwargs(),

Warning

The resource_class parameter was deprecated in django-import-export 3.0. Assign list or tuple with Resource(s) to resource_classes parameter now.

See also

Admin
available mixins and options.

Import confirmation

Importing in the Admin site is a two step process.

  1. Choose the file to import (screenshot).
  2. Review changes and confirm import (screenshot).

To support this, uploaded data is written to temporary storage after step 1, and read back for final import after step 2.

There are three mechanisms for temporary storage.

  1. Temporary file storage on the host server (default). This is suitable for development only. Use of temporary filesystem storage is not recommended for production sites.
  2. The Django cache.
  3. Django storage.

To modify which storage mechanism is used, please refer to the setting IMPORT_EXPORT_TMP_STORAGE_CLASS.

Temporary resources are removed when data is successfully imported after the confirmation step.

Your choice of temporary storage will be influenced by the following factors:

  • Sensitivity of the data being imported.
  • Volume and frequency of uploads.
  • File upload size.
  • Use of containers or load-balanced servers.

Warning

If users do not complete the confirmation step of the workflow, or if there are errors during import, then temporary resources may not be deleted. This will need to be understood and managed in production settings. For example, using a cache expiration policy or cron job to clear stale resources.

Using multiple resources

It is possible to set multiple resources both to import and export ModelAdmin classes. The ImportMixin, ExportMixin, ImportExportMixin and ImportExportModelAdmin classes accepts subscriptable type (list, tuple, …) as resource_classes parameter. The subscriptable could also be returned from one of the get_resource_classes(), get_import_resource_classes(), get_export_resource_classes() classes.

If there are multiple resources, the resource chooser appears in import/export admin form. The displayed name of the resource can be changed through the name parameter of the Meta class.

Use multiple resources:

from import_export import resources
from core.models import Book


class BookResource(resources.ModelResource):

    class Meta:
        model = Book


class BookNameResource(resources.ModelResource):

    class Meta:
        model = Book
        fields = ['id', 'name']
        name = "Export/Import only book names"


class CustomBookAdmin(ImportMixin, admin.ModelAdmin):
    resource_classes = [BookResource, BookNameResource]