Instanciate a chunk insided a mapped function in order to construct a dask array from scratch?

[guillaumeeb]

Hello again,

@eschalkargans

(1) Is it a good practice to initiate such arrays from scratch?

Well it’s definitely not a bad practice, but it depends on your use case!

@eschalkargans

My intuition is that it is the only way, eg when reading from multi-file datasets (like chunked Zarr arrays). If you have some examples of code instanciating such dask arrays from scratch, it would be useful!

I’m not sure I understand your point here. If you instanciate with Zarr, why not use from_zarr?

@eschalkargans

(2) If (1) is OK, I assume such mutability can only be used at the start of the processing chain, eg, the initial functions

Probably, but as mentioned in your other topic, things are still unclear to me.

@eschalkargans

(3) The only other way to mutate in-place a chunk of a dask array would be not to mutate it, but instead instanciating a copy of it

With that, you’re sure that you’ll don’t get any trouble.