Docs: how do I *update* a dataset on file?

[jeromekelleher]

I'm not finding any documentation how to do something like:

ds = sg.load_dataset(ds_path)    
ds = sg.count_variant_alleles(ds)
# Don't overwrite the whole thing, just write out the new variables so I don't have to 
# recompute them
sg.save_dataset(ds, ds_path) 

We have how do I save but that's not helping.

[tomwhite]

#347 has some discussion and code for this. We didn't quite agree on an API, so I'd be interested to see what you think works in your situation.

[jeromekelleher]

Nice, I'll try that out and report back.

[benjeffery]

I've been using this pattern:

        ds.update({"new_array_name": new_array})
        sgkit.save_dataset(ds.drop_vars(set(ds.data_vars) - {"new_array_name"}), ds_dir, mode="a")