Fixed #20468 -- Added loaddata --exclude option.

Thanks Alex Morozov for the initial patch.

django/core/management/commands/dumpdata.py

@@ -4,6 +4,7 @@ from collections import OrderedDict
 from django.apps import apps
 from django.core import serializers
 from django.core.management.base import BaseCommand, CommandError
+from django.core.management.utils import parse_apps_and_model_labels
 from django.db import DEFAULT_DB_ALIAS, router
 
 
@@ -81,21 +82,7 @@ class Command(BaseCommand):
         else:
             primary_keys = []
 
-        excluded_apps = set()
-        excluded_models = set()
-        for exclude in excludes:
-            if '.' in exclude:
-                try:
-                    model = apps.get_model(exclude)
-                except LookupError:
-                    raise CommandError('Unknown model in excludes: %s' % exclude)
-                excluded_models.add(model)
-            else:
-                try:
-                    app_config = apps.get_app_config(exclude)
-                except LookupError as e:
-                    raise CommandError(str(e))
-                excluded_apps.add(app_config)
+        excluded_models, excluded_apps = parse_apps_and_model_labels(excludes)
 
         if len(app_labels) == 0:
             if primary_keys:

django/core/management/commands/loaddata.py

@@ -13,6 +13,7 @@ from django.core import serializers
 from django.core.exceptions import ImproperlyConfigured
 from django.core.management.base import BaseCommand, CommandError
 from django.core.management.color import no_style
+from django.core.management.utils import parse_apps_and_model_labels
 from django.db import (
     DEFAULT_DB_ALIAS, DatabaseError, IntegrityError, connections, router,
     transaction,
@@ -52,13 +53,17 @@ class Command(BaseCommand):
             help='Ignores entries in the serialized data for fields that do not '
                  'currently exist on the model.',
         )
+        parser.add_argument(
+            '-e', '--exclude', dest='exclude', action='append', default=[],
+            help='An app_label or app_label.ModelName to exclude. Can be used multiple times.',
+        )
 
     def handle(self, *fixture_labels, **options):
-
         self.ignore = options['ignore']
         self.using = options['database']
         self.app_label = options['app_label']
         self.verbosity = options['verbosity']
+        self.excluded_models, self.excluded_apps = parse_apps_and_model_labels(options['exclude'])
 
         with transaction.atomic(using=self.using):
             self.loaddata(fixture_labels)
@@ -160,6 +165,9 @@ class Command(BaseCommand):
 
                 for obj in objects:
                     objects_in_fixture += 1
+                    if (obj.object._meta.app_config in self.excluded_apps or
+                            type(obj.object) in self.excluded_models):
+                        continue
                     if router.allow_migrate_model(self.using, obj.object.__class__):
                         loaded_objects_in_fixture += 1
                         self.models.add(obj.object.__class__)

django/core/management/utils.py

@@ -4,6 +4,7 @@ import os
 import sys
 from subprocess import PIPE, Popen
 
+from django.apps import apps as installed_apps
 from django.utils import six
 from django.utils.crypto import get_random_string
 from django.utils.encoding import DEFAULT_LOCALE_ENCODING, force_text
@@ -84,3 +85,30 @@ def get_random_secret_key():
     """
     chars = 'abcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*(-_=+)'
     return get_random_string(50, chars)
+
+
+def parse_apps_and_model_labels(labels):
+    """
+    Parse a list of "app_label.ModelName" or "app_label" strings into actual
+    objects and return a two-element tuple:
+        (set of model classes, set of app_configs).
+    Raise a CommandError if some specified models or apps don't exist.
+    """
+    apps = set()
+    models = set()
+
+    for label in labels:
+        if '.' in label:
+            try:
+                model = installed_apps.get_model(label)
+            except LookupError:
+                raise CommandError('Unknown model: %s' % label)
+            models.add(model)
+        else:
+            try:
+                app_config = installed_apps.get_app_config(label)
+            except LookupError as e:
+                raise CommandError(str(e))
+            apps.add(app_config)
+
+    return models, apps