[v3] reimplement / develop `Group.info` and `Array.info` properties

[jhamman]

Zarr Python 2 had nice info properties on the Group and Array classes. We haven't built these for v3 yet.

  >>> import zarr
  >>> z = zarr.zeros(1000000, chunks=100000, dtype='i4')
  >>> z.info
  Type               : zarr.core.Array
  Data type          : int32
  Shape              : (1000000,)
  Chunk shape        : (100000,)
  Order              : C
  Read-only          : False
  Compressor         : Blosc(cname='lz4', clevel=5, shuffle=SHUFFLE, blocksize=0)
  Store type         : zarr.storage.KVStore
  No. bytes          : 4000000 (3.8M)
  No. bytes stored   : 320
  Storage ratio      : 12500.0
  Chunks initialized : 0/10

Reference to stub in v3:

zarr-python/src/zarr/core/array.py

Lines 598 to 599 in 61683be

	async def info(self) -> None:
	raise NotImplementedError

[sanketverma1704]

Thanks for the issue, @jhamman. I'd like to work on this.

AFAIK we discussed, leaving out properties that require computation, i.e., the number of bytes, the number of bytes stored, the storage ratio, etc.

[jhamman]

@MSanKeys963 - I think that is a great place to start. We could also make the trigger for computation something that you have to opt into. Like Array.info(compute=True) or something like that.

[TomAugspurger]

I can take a shot at this quick.

[TomAugspurger]

I'd like to keep .info as a properly, like it was in v2. I think we can include fields requiring computation in an info_full or info_complete method.