fix formatting issues for list serializer validation fix

Author: saadullahaleem

rest_framework/serializers.py

@@ -592,7 +592,7 @@ def __init__(self, *args, **kwargs):
 
         if kwargs.get('instance', []) and kwargs.get('data', []):
             assert len(kwargs.get("data", [])) == len(
-            kwargs.get("instance", [])), 'Data and instance should have same length'
+                kwargs.get("instance", [])), 'Data and instance should have same length'
 
         super().__init__(*args, **kwargs)
         self.child.bind(field_name='', parent=self)

tests/test_serializer.py

@@ -2,6 +2,7 @@
 import pickle
 import re
 import sys
+import unittest
 from collections import ChainMap
 from collections.abc import Mapping
 
@@ -10,7 +11,6 @@
 
 from rest_framework import exceptions, fields, relations, serializers
 from rest_framework.fields import Field
-
 from .models import (
     ForeignKeyTarget, NestedForeignKeySource, NullableForeignKeySource
 )
@@ -787,9 +787,6 @@ def validate_value(self, value):
         return value
 
 
-import unittest
-
-
 class TestMultipleObjectsValidation(unittest.TestCase):
     def setUp(self):
         self.objs = [
@@ -818,10 +815,10 @@ def test_multiple_objects_are_validated_separately(self):
     def test_exception_raised_when_data_and_instance_length_different(self):
 
         with self.assertRaises(AssertionError):
-            serializer = MyClassSerializer(
+            MyClassSerializer(
                 data=[{'value': 'set', 'id': instance.id} for instance in
                       self.objs],
                 instance=self.objs[:-1],
                 many=True,
                 partial=True,
-            )
+            )