Functions
std::unique_ptr< column >	cudf::lists::count_elements (lists_column_view const &input, rmm::cuda_stream_view stream=cudf::get_default_stream(), rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Returns a numeric column containing the number of rows in each list element in the given lists column. More...

Detailed Description

Function Documentation

std::unique_ptr<column> cudf::lists::count_elements	(	lists_column_view const &	input,
		rmm::cuda_stream_view	stream = `cudf::get_default_stream()`,
		rmm::mr::device_memory_resource *	mr = `rmm::mr::get_current_device_resource()`
	)

Returns a numeric column containing the number of rows in each list element in the given lists column.

The output column will have the same number of rows as the input lists column. Each output[i] will be input[i].size().

l = { {1, 2, 3}, {4}, {5, 6} }
r = count_elements(l)
r is now {3, 1, 2}

Any null input element will result in a corresponding null entry in the output column.

Parameters

input	Input lists column
stream	CUDA stream used for device memory operations and kernel launches
mr	Device memory resource used to allocate the returned column's device memory