Attribute nbytes of slice will return the value corresponding to the whole structure

[asfimport]

Whether for tables/arrays, slicing and then calling nbytes will return the value for the whole struct. I don't know if this is a bug or the desired behaviour (and if it is I would argue that it should return a result relative to the slice, and also ask if there is any way to get the memory size of my slice?).

 

import pyarrow

pyarrow.__version__

>>> 6.0.0

table = pyarrow.Table.from_arrays([pyarrow.array(['foo', 'bar', 'qux'], type=pyarrow.string())], names=["a"])

table.num_rows

>>> 3

table.nbytes

>>> 25

table.slice(0, 2).num_rows

>>> 2

table.slice(0, 2).nbytes

>>> 25

Reporter: Adrien Hoarau

_{Note: This issue was originally created as ARROW-15054. Please see the migration documentation for further details.}