Question about reverse mapping from key to slice.

[JoOkuma]

Hi, I'm not sure what's the best place to ask zarr questions so I'm posting this here.

I'm trying to iterate as fast as possible over a zarr.Array with very few chunks initialized.
I couldn't find a method for this so I'm implementing my own function that will return a sequence of chunks and their respective slices.

I started with this function to get the chunks' key:

def get_initialized_keys(array: Array):
    # key pattern for chunk keys
    prog = re.compile(r'\.'.join([r'\d+'] * min(1, array.ndim)))

    # yield chunk keys
    for k in listdir(array.chunk_store, array._path):
        if prog.match(k):
            yield k

Is there any API to get the reverse BasicIndexer behavior, so for a given key (chunk_selection) I would get its slice (out_selection)?

Thanks

[MSanKeys963]

Hi @JoOkuma.

Thanks for posting your question.

I'm not sure what's the best place to ask zarr questions

As it happens we have just opened discussions section in zarr-python and it'd be great if you could post your question there!

Thanks!

[joshmoore]

Migrated.

[jakirkham]

Maybe worth reading over issue ( #518 )