Question

Well, I think the question explains itself.

I have two instances of a Django Model and I would like to know which fields differ.

How could you do this in a smart way?

Cheers!

Answer 1

Lets says obj1 and obj2 are 2 instances of the model MyModel.

To know which fields differ on two instances of a Django model, we first get all the fields of a model and store it in a variable my_model_fields.

my_model_fields = MyModel._meta.get_all_field_names() # gives me the list of all the model fields defined in it

Then we apply filter() with lambda to know which fields differ between them.

filter(lambda field: getattr(obj1,field,None)!=getattr(obj2,field,None), my_model_fields)

The filter() function will return me the list of model fields which differ between the two instances.

Answer 2

这就是我在序列化器和deepdiff的帮助下获得两个实例之间差异的方式。为什么是序列化器？因为我们必须获取实例的整个嵌套数据进行比较。

  from deepdiff import DeepDiff
  .
  .
  .
  old_data = modelserilaizer(instance1).data
  new_data = modelserilaizer(instance2).data
  instance_diff = DeepDiff(old_data, new_data, ignore_order=True)
  # output {'values_changed': {"root['item'][3]['rr'][2]['rate']": {'new_value': '0.03', 'old_value': '0.02'}}}
  if "values_changed" in instance_diff:
    # do you work here

Find which fields are different between two instances of the same Model

2 个答案: