old_contents: import contextlib
  import errno
  import os
  import time
  import tempfile
  from django.utils import importlib
  
  
  def import_from_classname(class_name_str):
      module, class_name = class_name_str.rsplit('.', 1)
      Class = getattr(importlib.import_module(module), class_name)
      return Class
  
  
  def ctypes_dict():
      from django.contrib.contenttypes.models import ContentType
  
      values = ContentType.objects.values_list('app_label', 'model', 'id')
      ctypes = {}
      [ctypes.update({"%s.%s" % x[:2]: x[2]}) for x in values]
      return ctypes
  
  
  @contextlib.contextmanager
  def filelock(name, wait_delay=.1):
      path = os.path.join(tempfile.gettempdir(), name)
      while True:
          try:
              fd = os.open(path, os.O_CREAT | os.O_EXCL | os.O_RDWR)
          except OSError as e:
              if e.errno != errno.EEXIST:
                  raise
              time.sleep(wait_delay)
              continue
          else:
              break
      try:
          yield fd
      finally:
          os.close(fd)
          os.unlink(path)
  
new_contents: import contextlib
  import errno
  import os
  import time
  import tempfile
  import importlib
  
  
  def import_from_classname(class_name_str):
      module, class_name = class_name_str.rsplit('.', 1)
      Class = getattr(importlib.import_module(module), class_name)
      return Class
  
  
  def ctypes_dict():
      from django.contrib.contenttypes.models import ContentType
  
      values = ContentType.objects.values_list('app_label', 'model', 'id')
      ctypes = {}
      [ctypes.update({"%s.%s" % x[:2]: x[2]}) for x in values]
      return ctypes
  
  
  @contextlib.contextmanager
  def filelock(name, wait_delay=.1):
      path = os.path.join(tempfile.gettempdir(), name)
      while True:
          try:
              fd = os.open(path, os.O_CREAT | os.O_EXCL | os.O_RDWR)
          except OSError as e:
              if e.errno != errno.EEXIST:
                  raise
              time.sleep(wait_delay)
              continue
          else:
              break
      try:
          yield fd
      finally:
          os.close(fd)
          os.unlink(path)
  
subject: Remove deprecated django.utils.importlib