org.datavec.dataframe.io.csv

Class CsvReader

java.lang.Object

org.datavec.dataframe.io.csv.CsvReader

@Immutable
public class CsvReader
extends java.lang.Object

Method Summary

Modifier and Type	Method and Description
static Table	detectedColumnTypes(java.lang.String csvFileName, boolean header, char delimiter) Returns the structure of the table given by csvFileName as detected by analysis of a sample of the data
static Table	headerOnly(ColumnType[] types, boolean header, char columnSeparator, java.lang.String fileName) Returns a Table constructed from a CSV File with the given file name
static Table	headerOnly(java.lang.String name, ColumnType[] types, boolean header, char columnSeparator, java.io.InputStream stream) Returns a Table constructed from a CSV File with the given file name
static java.lang.String	printColumnTypes(java.lang.String csvFileName, boolean header, char delimiter) Returns a string representation of the file types in file csvFilename, as determined by the type-detection algorithm
static Table	read(ColumnType[] types, boolean header, char columnSeparator, java.lang.String fileName) Returns a Table constructed from a CSV File with the given file name
static Table	read(ColumnType[] types, java.lang.String... fileNames) Constructs and returns a table from one or more CSV files, all containing the same column types
static Table	read(java.lang.String fileName, boolean header, char delimiter) Retuns the given file after autodetecting the column types, or trying to
static Table	read(java.lang.String tableName, ColumnType[] types, boolean header, char columnSeparator, java.io.InputStream stream)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

read

public static Table read(ColumnType[] types,
                         java.lang.String... fileNames)
                  throws java.io.IOException

Constructs and returns a table from one or more CSV files, all containing the same column types

This constructor assumes the files have a one-line header, which is used to populate the column names, and that they use a comma to separate between columns.

Throws:

java.io.IOException - If there is an issue reading any of the files

read

public static Table read(ColumnType[] types,
                         boolean header,
                         char columnSeparator,
                         java.lang.String fileName)
                  throws java.io.IOException

Returns a Table constructed from a CSV File with the given file name

The @code{fileName} is used as the initial table name for the new table

Parameters:

types - An array of the types of columns in the file, in the order they appear

header - Is the first row in the file a header?

columnSeparator - the delimiter

fileName - The fully specified file name. It is used to provide a default name for the table

Returns:

A Table containing the data in the csv file.

Throws:

java.io.IOException

read

public static Table read(java.lang.String fileName,
                         boolean header,
                         char delimiter)
                  throws java.io.IOException

Retuns the given file after autodetecting the column types, or trying to

Parameters:

fileName - The name of the file to load

header - True if the file has a single header row. False if it has no header row. Multi-line headers are not supported

delimiter - a char that divides the columns in the source file, often a comma or tab

Returns:

A table containing the data from the file

Throws:

java.io.IOException

read

public static Table read(java.lang.String tableName,
                         ColumnType[] types,
                         boolean header,
                         char columnSeparator,
                         java.io.InputStream stream)
                  throws java.io.IOException

Throws:

java.io.IOException

headerOnly

public static Table headerOnly(java.lang.String name,
                               ColumnType[] types,
                               boolean header,
                               char columnSeparator,
                               java.io.InputStream stream)
                        throws java.io.IOException

Returns a Table constructed from a CSV File with the given file name

The @code{fileName} is used as the initial table name for the new table

Parameters:

types - An array of the types of columns in the file, in the order they appear

header - Is the first row in the file a header?

columnSeparator - the delimiter

name - The fully specified file name. It is used to provide a default name for the table

Returns:

A Table containing the data in the csv file.

Throws:

java.io.IOException

headerOnly

public static Table headerOnly(ColumnType[] types,
                               boolean header,
                               char columnSeparator,
                               java.lang.String fileName)
                        throws java.io.IOException

Returns a Table constructed from a CSV File with the given file name

The @code{fileName} is used as the initial table name for the new table

Parameters:

types - An array of the types of columns in the file, in the order they appear

header - Is the first row in the file a header?

columnSeparator - the delimiter

fileName - The fully specified file name. It is used to provide a default name for the table

Returns:

A Relation containing the data in the csv file.

Throws:

java.io.IOException

detectedColumnTypes

public static Table detectedColumnTypes(java.lang.String csvFileName,
                                        boolean header,
                                        char delimiter)
                                 throws java.io.IOException

Returns the structure of the table given by csvFileName as detected by analysis of a sample of the data

Throws:

java.io.IOException

printColumnTypes

public static java.lang.String printColumnTypes(java.lang.String csvFileName,
                                                boolean header,
                                                char delimiter)
                                         throws java.io.IOException

Returns a string representation of the file types in file csvFilename, as determined by the type-detection algorithm

This method is intended to help analysts quickly fix any erroneous types, by printing out the types in a format such that they can be edited to correct any mistakes, and used in an array literal

For example:

LOCAL_DATE, // 0 date SHORT_INT, // 1 approval CATEGORY, // 2 who

Note that the types are array separated, and that the index position and the column name are printed such that they would be interpreted as comments if you paste the output into an array:

ColumnType[] types = { LOCAL_DATE, // 0 date SHORT_INT, // 1 approval CATEGORY, // 2 who }

Throws:

java.io.IOException