issue_comments: 1196538785

In the example the naming and meaning of the arguments of the __init__ method are different from the Dataset base class.

Subclassing is often more reliable when it adheres to the Liskov Substitution Principle which states that objects of a superclass should be replaceable with objects of its subclasses and in other words: a subclass should only add functionality and not reduce it.

There are some other workarounds though:

If all you need is a convenient custom constructor then you could add a classmethod factory method to your subclass or even just use a plain function which returns a Dataset.

Another option is to convert your MyDataset instances to plain Dataset instances before passing them into xarray.concat, e.g. xarray.concat([ds.to_dataset() for ds in [ds1, ds2, ds3]], dim="coord1")

where your subclass may define as a convenience method:

def to_dataset(self): """Convert to plain Dataset.""" return xarray.Dataset(self, attrs=self.attrs)

Thank you for the answer. I'll look into implementing one of your suggestions (they're much better than what I had in mind).

I still don't understand the change that causes the error, though. If you want to instantiate a Dataset object, which you clearly do according to the args you pass in, why did that line have to be changed from explicitly calling Dataset? (By "you" I don't mean you personally, unless you actually made the change :) )