Character Types

Files
file	char_types.hpp
file	char_types_enum.hpp

Enumerations
enum	cudf::strings::string_character_types : uint32_t {   cudf::strings::DECIMAL = 1 << 0 , cudf::strings::NUMERIC = 1 << 1 , cudf::strings::DIGIT = 1 << 2 , cudf::strings::ALPHA = 1 << 3 ,   cudf::strings::SPACE = 1 << 4 , cudf::strings::UPPER = 1 << 5 , cudf::strings::LOWER = 1 << 6 , cudf::strings::ALPHANUM = DECIMAL | NUMERIC | DIGIT | ALPHA ,   cudf::strings::CASE_TYPES = UPPER | LOWER , cudf::strings::ALL_TYPES = ALPHANUM | CASE_TYPES | SPACE }
	Character type values. These types can be or'd to check for any combination of types. More...

Functions
std::unique_ptr< column >	cudf::strings::all_characters_of_type (strings_column_view const &input, string_character_types types, string_character_types verify_types=string_character_types::ALL_TYPES, rmm::cuda_stream_view stream=cudf::get_default_stream(), rmm::device_async_resource_ref mr=cudf::get_current_device_resource_ref())
	Returns a boolean column identifying string entries where all characters are of the type specified. More...
std::unique_ptr< column >	cudf::strings::filter_characters_of_type (strings_column_view const &input, string_character_types types_to_remove, string_scalar const &replacement=string_scalar(""), string_character_types types_to_keep=string_character_types::ALL_TYPES, rmm::cuda_stream_view stream=cudf::get_default_stream(), rmm::device_async_resource_ref mr=cudf::get_current_device_resource_ref())
	Filter specific character types from a column of strings. More...
constexpr string_character_types	cudf::strings::operator| (string_character_types lhs, string_character_types rhs)
	OR operator for combining string_character_types. More...
constexpr string_character_types &	cudf::strings::operator|= (string_character_types &lhs, string_character_types rhs)
	Compound assignment OR operator for combining string_character_types. More...

Detailed Description

Enumeration Type Documentation

string_character_types

enum cudf::strings::string_character_types : uint32_t

Character type values. These types can be or'd to check for any combination of types.

This cannot be turned into an enum class because or'd entries can result in values that are not in the class. For example, combining NUMERIC|SPACE is a valid, reasonable combination but does not match to any explicitly named enumerator.

Enumerator
DECIMAL	all decimal characters
NUMERIC	all numeric characters
DIGIT	all digit characters
ALPHA	all alphabetic characters
SPACE	all space characters
UPPER	all upper case characters
LOWER	all lower case characters
ALPHANUM	all alphanumeric characters
CASE_TYPES	all case-able characters
ALL_TYPES	all character types

Definition at line 38 of file char_types_enum.hpp.

Function Documentation

all_characters_of_type()

std::unique_ptr<column> cudf::strings::all_characters_of_type	(	strings_column_view const &	input,
		string_character_types	types,
		string_character_types	verify_types = string_character_types::ALL_TYPES,
		rmm::cuda_stream_view	stream = cudf::get_default_stream(),
		rmm::device_async_resource_ref	mr = cudf::get_current_device_resource_ref()
	)

Returns a boolean column identifying string entries where all characters are of the type specified.

The output row entry will be set to false if the corresponding string element is empty or has at least one character not of the specified type. If all characters fit the type then true is set in that output row entry.

To ignore all but specific types, set the verify_types to those types which should be checked. Otherwise, the default ALL_TYPES will verify all characters match types.

Example:
s = ['ab', 'a b', 'a7', 'a B']
b1 = s.all_characters_of_type(s,LOWER)
b1 is [true, false, false, false]
b2 = s.all_characters_of_type(s,LOWER,LOWER|UPPER)
b2 is [true, true, true, false]

Any null row results in a null entry for that row in the output column.

Parameters

input	Strings instance for this operation
types	The character types to check in each string
verify_types	Only verify against these character types. Default ALL_TYPES means return true iff all characters match types.
stream	CUDA stream used for device memory operations and kernel launches
mr	Device memory resource used to allocate the returned column's device memory

Returns

New column of boolean results for each string

filter_characters_of_type()

std::unique_ptr<column> cudf::strings::filter_characters_of_type	(	strings_column_view const &	input,
		string_character_types	types_to_remove,
		string_scalar const &	replacement = string_scalar(""),
		string_character_types	types_to_keep = string_character_types::ALL_TYPES,
		rmm::cuda_stream_view	stream = cudf::get_default_stream(),
		rmm::device_async_resource_ref	mr = cudf::get_current_device_resource_ref()
	)

Filter specific character types from a column of strings.

To remove all characters of a specific type, set that type in types_to_remove and set types_to_keep to ALL_TYPES.

To filter out characters NOT of a select type, specify ALL_TYPES for types_to_remove and which types to not remove in types_to_keep.

Example:
s = ['ab', 'a b', 'a7bb', 'A7B234']
s1 = s.filter_characters_of_type(s,NUMERIC,"",ALL_TYPES)
s1 is ['ab', 'a b', 'abb', 'AB']
s2 = s.filter_characters_of_type(s,ALL_TYPES,"-",LOWER)
s2 is ['ab', 'a-b', 'a-bb', '------']

In s1 all NUMERIC types have been removed. In s2 all non-LOWER types have been replaced.

One but not both parameters types_to_remove and types_to_keep must be set to ALL_TYPES.

Any null row results in a null entry for that row in the output column.

Exceptions

cudf::logic_error

if neither or both types_to_remove and types_to_keep are set to ALL_TYPES.

Parameters

input	Strings instance for this operation
types_to_remove	The character types to check in each string. Use ALL_TYPES here to specify types_to_keep instead.
replacement	The replacement character to use when removing characters
types_to_keep	Default ALL_TYPES means all characters of types_to_remove will be filtered.
mr	Device memory resource used to allocate the returned column's device memory
stream	CUDA stream used for device memory operations and kernel launches

Returns

New strings column with the characters of specified types filtered out and replaced by the specified replacement string

operator|()

constexpr string_character_types cudf::strings::operator| ( string_character_types  lhs, string_character_types  rhs  )

constexpr

OR operator for combining string_character_types.

Parameters

lhs	left-hand side of OR operation
rhs	right-hand side of OR operation

Returns

combined string_character_types

Definition at line 58 of file char_types_enum.hpp.

operator|=()

constexpr string_character_types& cudf::strings::operator|= ( string_character_types &  lhs, string_character_types  rhs  )

constexpr

Compound assignment OR operator for combining string_character_types.

Parameters

lhs	left-hand side of OR operation
rhs	right-hand side of OR operation

Returns

Reference to lhs after combining lhs and rhs

Definition at line 72 of file char_types_enum.hpp.