Can I add custom user-attributes at once?

[paulshuker]

Hey,

If I have a zarr.Group that is using a ZipStore in zarr 2.18, is there a way to add two attributes to the group in one go? The reason I ask is because if I add one after the other, like so:

group.attrs["a"] = 0
group.attrs["b"] = 1

I get a warning on the second addition as a ZipStore cannot modify existing files as far as I understand. I checked the Tutorial and the Group API but I could not find anything. Thanks.

[TomAugspurger]

You can use .update:

In [1]: import zarr

In [2]: store = zarr.storage.MemoryStore()

In [4]: g = zarr.create_group(store, path="g")

In [6]: g.attrs.update({"a": 1, "b": 2})

A PR improving the documentation here would be very welcome.

Edit: actually, maybe the recommended way is to use Group.update_attributes? My example might have only worked since it was an in-memory store...

[d-v-b]

Another option if you know all of your attributes when you create the group: you can specify the attributes at group creation time via the attributes keyword argument to create_group.