We developed several utilities that computes / accesses certain properties of Arrays and wonder if they make sense to get them into the upstream (into both the C++ API and pyarrow) and assuming yes, where is the best place to put them?
Maybe I have overlooked existing APIs that already do the same.. in that case please point out.
Returns lengths of lists in a ListArray, as a Int32Array (or Int64Array for large lists). For example:
[[1, 2, 3], , None] => [3, 0, 0] (or [3, 0, None], but we hope the returned array can be converted to numpy)
Returns the total byte size of a BinaryArray (basically offset[len - 1] - offset).
Alternatively, a BinaryArray::Flatten() -> Uint8Array would work.
Returns the array's null bitmap as a UInt8Array (which can be efficiently converted to a bool numpy array)
Makes a int32 array of the same length as the flattened ListArray. returned_array[i] == j means i-th element in the flattened ListArray came from j-th list in the ListArray.
For example [[1,2,3], , None, [4,5]] => [0, 0, 0, 3, 3]