issue_comments: 539240950

Would that make any sense that the xr.DataSet.copy() method also return a copy of the accessors ?

It's been discussed above in this same thread. It's impossible without breaking the accessor API, as it would require you (the accessor developer) to define a copy method. The more high level discussion is that the statefulness of the accessor is something that is OK to use for caching and performance improvements, and not OK for storing functional information like yours.

Have you considered storing a flag in Variable.attrs instead?

```python

def add(self, da):
    da.attrs["cleanable"] = True
    self.obj[da.name] = da
    return self.obj

def clean(self):
    return self.obj.drop([
        k for k, v in self.obj.variables.items()
        if v.attrs.get("cleanable")
    ])

```