turi::dataframe_t Struct Reference

#include <core/storage/sframe_data/dataframe.hpp>

Public Member Functions
void	read_csv (const std::string &path, char delimiter, bool use_header)
size_t	nrows () const
bool	empty () const
void	set_type (std::string key, flex_type_enum type)
size_t	ncols () const
	Returns the number of columns in the dataframe.
bool	contains (std::string key) const
bool	contains_nan (std::string key) const
std::pair< flex_type_enum, std::vector< flexible_type > & >	operator[] (std::string key)
std::pair< flex_type_enum, const std::vector< flexible_type > & >	operator[] (std::string key) const
void	print () const
void	set_column (std::string key, const std::vector< flexible_type > &val, flex_type_enum type)
void	set_column (std::string key, std::vector< flexible_type > &&val, flex_type_enum type)
void	remove_column (std::string key)
void	save (oarchive &oarc) const
	Serializer.
void	load (iarchive &iarc)
	Deserializer.
void	clear ()
	Clears the contents of the dataframe.

Public Attributes
std::vector< std::string >	names
	A vector storing the name of columns.
std::map< std::string, flex_type_enum >	types
	A map from the column name to the type of the column.
std::map< std::string, std::vector< flexible_type > >	values

Detailed Description

Type that represents a Pandas-like dataframe: A in memory column-wise representation of a table. The dataframe_t is simply a map from column name to a column of records, where every column is the same length, and all values within a column have the same type. This is also the type used for transferring between pandas dataframe objects and C++.

Each cell in the dataframe is represented by a flexible_type object, while this technically allows every cell to be an arbitrary type, we do not permit that behavior. We require and assume that every cell in a column be of the same type. This is with the exception of empty cells (NaNs in Pandas) which are of type UNDEFINED.

Definition at line 39 of file dataframe.hpp.

Member Function Documentation

contains()

bool turi::dataframe_t::contains ( std::string  key ) const

inline

Returns true if the dataframe contains a column with the given name.

Definition at line 94 of file dataframe.hpp.

contains_nan()

bool turi::dataframe_t::contains_nan ( std::string  key ) const

inline

Returns true if the column contains undefined flexible_type value.

Definition at line 101 of file dataframe.hpp.

empty()

bool turi::dataframe_t::empty ( ) const

inline

Returns true if the dataframe is empty.

Definition at line 77 of file dataframe.hpp.

nrows()

size_t turi::dataframe_t::nrows ( ) const

inline

Returns the number of rows in the dataframe

Definition at line 69 of file dataframe.hpp.

operator[]() [1/2]

std::pair< flex_type_enum, std::vector<flexible_type>&> turi::dataframe_t::operator[] ( std::string  key )

inline

Column index operator. Can be used to extract a column from the dataframe. Returns a pair of (type, reference to column)

Definition at line 120 of file dataframe.hpp.

operator[]() [2/2]

std::pair< flex_type_enum, const std::vector<flexible_type>&> turi::dataframe_t::operator[] ( std::string  key ) const

inline

Const column index operator. Can be used to extract a column from the dataframe. Returns a pair of (type, reference to column)

Definition at line 129 of file dataframe.hpp.

print()

void turi::dataframe_t::print

(

)

const

Prints the contents of the dataframe to std::cerr

read_csv()

void turi::dataframe_t::read_csv	(	const std::string &	path,
		char	delimiter,
		bool	use_header
	)

Fill the dataframe with the content from a csv file.

Parameters

remove_column()

void turi::dataframe_t::remove_column

(

std::string

key

)

Remove the column.

set_column() [1/2]

void turi::dataframe_t::set_column	(	std::string	key,
		const std::vector< flexible_type > &	val,
		flex_type_enum	type
	)

Sets the value of a column of the dataframe.

set_column() [2/2]

void turi::dataframe_t::set_column	(	std::string	key,
		std::vector< flexible_type > &&	val,
		flex_type_enum	type
	)

Sets the value of a column of the dataframe, consuming the vector value

set_type()

void turi::dataframe_t::set_type	(	std::string	key,
		flex_type_enum	type
	)

Convert the values in the column into the specified type. Throws an exception if the column is not found, or the conversion cannot be made.

Member Data Documentation

values

std::map<std::string, std::vector<flexible_type> > turi::dataframe_t::values

A map from the column name to the values of the column. Every column must have the same length, and all values within a column must be of the same type. The UNDEFINED type is an exception to the rule and may be used anywhere to designate an empty entry.

Definition at line 51 of file dataframe.hpp.

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The documentation for this struct was generated from the following file:

• core/storage/sframe_data/dataframe.hpp