Slicing

Files
file	slice.hpp

Functions
std::unique_ptr< column >	cudf::strings::slice_strings (strings_column_view const &strings, numeric_scalar< size_type > const &start=numeric_scalar< size_type >(0, false), numeric_scalar< size_type > const &stop=numeric_scalar< size_type >(0, false), numeric_scalar< size_type > const &step=numeric_scalar< size_type >(1), rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Returns a new strings column that contains substrings of the strings in the provided column. More...
std::unique_ptr< column >	cudf::strings::slice_strings (strings_column_view const &strings, column_view const &starts, column_view const &stops, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Returns a new strings column that contains substrings of the strings in the provided column using unique ranges for each string. More...

Detailed Description

Function Documentation

slice_strings() [1/2]

std::unique_ptr<column> cudf::strings::slice_strings	(	strings_column_view const &	strings,
		column_view const &	starts,
		column_view const &	stops,
		rmm::mr::device_memory_resource *	mr = rmm::mr::get_current_device_resource()
	)

Returns a new strings column that contains substrings of the strings in the provided column using unique ranges for each string.

The character positions to retrieve in each string are specified in the starts and stops integer columns. If a start position is outside a string's length, an empty string is returned for that entry. If a stop position is past the end of a string's length, the end of the string is used for stop position for that string. Any stop position value set to -1 will indicate to use the end of the string as the stop position for that string.

Null string entries will return null output string entries.

The starts and stops column must both be the same integer type and must be the same size as the strings column.

Example:
s = ["hello", "goodbye"]
starts = [ 1, 2 ]
stops = [ 5, 4 ]
r = slice_strings(s,starts,stops)
r is now ["ello","od"]

Exceptions

cudf::logic_error	if starts or stops is a different size than the strings column.
cudf::logic_error	if starts and stops are not same integer type.
cudf::logic_error	if starts or stops contains nulls.

Parameters

strings	Strings column for this operation.
starts	First character positions to begin the substring.
stops	Last character (exclusive) positions to end the substring.
mr	Device memory resource used to allocate the returned column's device memory.

Returns

New strings column with sorted elements of this instance.

slice_strings() [2/2]

std::unique_ptr<column> cudf::strings::slice_strings	(	strings_column_view const &	strings,
		numeric_scalar< size_type > const &	start = numeric_scalar< size_type >(0, false),
		numeric_scalar< size_type > const &	stop = numeric_scalar< size_type >(0, false),
		numeric_scalar< size_type > const &	step = numeric_scalar< size_type >(1),
		rmm::mr::device_memory_resource *	mr = rmm::mr::get_current_device_resource()
	)

Returns a new strings column that contains substrings of the strings in the provided column.

The character positions to retrieve in each string are [start,stop). If the start position is outside a string's length, an empty string is returned for that entry. If the stop position is past the end of a string's length, the end of the string is used for stop position for that string.

Null string entries will return null output string entries.

Example:
s = ["hello", "goodbye"]
r = slice_strings(s,2,6)
r is now ["llo","odby"]
r2 = slice_strings(s,2,5,2)
r2 is now ["lo","ob"]

Parameters

strings	Strings column for this operation.
start	First character position to begin the substring.
stop	Last character position (exclusive) to end the substring.
step	Distance between input characters retrieved.
mr	Device memory resource used to allocate the returned column's device memory.

Returns

New strings column with sorted elements of this instance.