Possibility to see what changes with a save?
Well, peewee knows that you set attributes so those are stored in the `dirty_fields` attribute. But there's no checking to see if it differed from the previous value. Any additional logic will have to live in your app itself.
 You can do `model.save(only=model.dirty_fields)`, if you just want to save those that were "set", but it doesn't track actual changes to the underyling value.
 Alright thanks. In that case I will need to build something myself.

Thanks!
 Why wouldn't peewee check whether values have actually changed? Speed?

And would this be a good way to implement it?

```python
class BaseModel(Model):
    class Meta:
        database = database
        only_save_dirty = True

    def __setattr__(self, name, value):
        if not hasattr(self, name) or getattr(self, name) is not value:
            return super().__setattr__(name, value)
```
Let's say I've got a `User` model from which I start a new record as follows:

```
u = User()
u.username = 'bob'
u.location = 'home'
u.save()
```

I now use the same user instance and write two values of which one is the same:

```
u.username = 'bob'  # stays the same
u.location = 'work'  # changes
u.save()
```

When saving the updated values, is there a way with Peewee to know which of the values changed (i.e.: `location`), without actually comparing them with the existing values?

Ive got a model with about 50 fields to which I simply save the values of a json object. It would be so much easier if I could get the differences, instead of me needing to compare all those 50 values manually.
