  from django.utils.safestring import SafeText
  from django.utils.translation import ugettext_lazy as _
  
  from rest_framework import permissions, serializers, status
  from rest_framework.compat import MutableMapping, coreapi
  from rest_framework.decorators import action
  from rest_framework.renderers import (
      AdminRenderer, BaseRenderer, BrowsableAPIRenderer, DocumentationRenderer,
      HTMLFormRenderer, JSONRenderer, SchemaJSRenderer, StaticHTMLRenderer
  )
 
</s> remove from rest_framework.compat import Mapping, postgres_fields
 </s> add from rest_framework.compat import postgres_fields </s> remove from rest_framework.compat import Mapping
 </s> add  </s> remove     Mapping, MaxLengthValidator, MaxValueValidator, MinLengthValidator,
 </s> add     MaxLengthValidator, MaxValueValidator, MinLengthValidator,
from rest_framework.compat import coreapi
  from django.utils.safestring import SafeText
  from django.utils.translation import ugettext_lazy as _
  
  from rest_framework import permissions, serializers, status
from rest_framework.compat import coreapi
  from rest_framework.decorators import action
  from rest_framework.renderers import (
      AdminRenderer, BaseRenderer, BrowsableAPIRenderer, DocumentationRenderer,
      HTMLFormRenderer, JSONRenderer, SchemaJSRenderer, StaticHTMLRenderer
  )
keep keep keep keep replace keep keep keep keep keep
 Remove unnecessary compatibility shims from rest_framework/compat.py (#6631)

For Python 3, collections.abc.Mapping and collections.abc.MutableMapping
are always available from the stdlib. 
tests/test_renderers.py