使用Image.copy遞歸deepcopy的

Question

我有這個模型複製構造器basemodel：

class BaseModel(models.Model): 
    def __init__(self, *args, **kwargs): 
     super().__init__(*args, **kwargs) 
     self.original = copy.deepcopy(self 

我的問題是，一些車型有ImageField的，當我嘗試複製，我得到AttributeError的。我發現這個錯誤的解決方案here，說「使用image.copy（），而不是copy.deepcopy（）。

我可以實現image.copy（）在遞歸deepcopy當字段是圖像？

非常感謝

編輯：這是跟蹤：

Traceback: 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/PIL/ImageFile.py" in load 

139. read = self.load_read 

During handling of the above exception ('JpegImageFile' object has no attribute 'load_read'), another exception occurred: 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/django/core/handlers/exception.py" in inner 

39. response = get_response(request) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/django/core/handlers/base.py" in _get_response 

187. response = self.process_exception_by_middleware(e, request) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/django/core/handlers/base.py" in _get_response 

185. response = wrapped_callback(request, *callback_args, **callback_kwargs) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/django/views/decorators/csrf.py" in wrapped_view 

58. return view_func(*args, **kwargs) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/django/views/generic/base.py" in view 

68. return self.dispatch(request, *args, **kwargs) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/rest_framework/views.py" in dispatch 

477. response = self.handle_exception(exc) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/rest_framework/views.py" in handle_exception 

437. self.raise_uncaught_exception(exc) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/rest_framework/views.py" in dispatch 

474. response = handler(request, *args, **kwargs) 

File "/home/imontilla/PycharmProjects/api/apps/chats/api.py" in put 

107. return self.response_or_errors(serializer, respond_with=serializers.ChatMessageOutputSerializer) 

File "/home/imontilla/PycharmProjects/api/apps/core/generics.py" in response_or_errors 

31. instance = serializer.save(**kwargs) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/rest_framework/serializers.py" in save 

214. self.instance = self.create(validated_data) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/rest_framework/serializers.py" in create 

902. instance = ModelClass.objects.create(**validated_data) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/django/db/models/manager.py" in manager_method 

85. return getattr(self.get_queryset(), name)(*args, **kwargs) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/django/db/models/query.py" in create 

397. obj = self.model(**kwargs) 

File "/home/imontilla/PycharmProjects/api/apps/core/models.py" in __init__ 

22. self.original_instance = copy.deepcopy(self) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/copy.py" in deepcopy 

182. y = _reconstruct(x, rv, 1, memo) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/copy.py" in _reconstruct 

297. state = deepcopy(state, memo) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/copy.py" in deepcopy 

155. y = copier(x, memo) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/copy.py" in _deepcopy_dict 

243. y[deepcopy(key, memo)] = deepcopy(value, memo) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/copy.py" in deepcopy 

182. y = _reconstruct(x, rv, 1, memo) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/copy.py" in _reconstruct 

297. state = deepcopy(state, memo) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/copy.py" in deepcopy 

155. y = copier(x, memo) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/copy.py" in _deepcopy_dict 

243. y[deepcopy(key, memo)] = deepcopy(value, memo) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/copy.py" in deepcopy 

174. rv = reductor(4) 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/PIL/Image.py" in __getstate__ 

639. self.getpalette(), 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/PIL/Image.py" in getpalette 

1196. self.load() 

File "/home/imontilla/.virtualenvs/petycash-django/lib/python3.5/site-packages/PIL/ImageFile.py" in load 

143. read = self.fp.read 

Exception Type: AttributeError at /chats/6fbd9f3e87f945b99969b2c53e35eb66/messages/image/ 

Exception Value: 'NoneType' object has no attribute 'read' 

Answer 1

我認爲最好的方法是一種方法copy添加到您的類中的這個方法，你可以控制的方式複製具有不同類型的對象。

class BaseModel(models.Model): 
    def __init__(self, *args, **kwargs): 
     super().__init__(*args, **kwargs) 
     self.original = self.copy() 

    def copy(self): 
     clone = copy.copy(self) # to copy __dict__ only 
     for key, value in clone.__dict__.items(): 
      if isinstance(value, BaseModel): 
       clone.__dict__[key] = value.copy() # recoursively 
      elif isinstance(value, Image): 
       clone.__dict__[key] = value.copy() 
      else: 
       clone.__dict__[key] = copy.deepcopy(value) 
     return clone