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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System.IO;
using Microsoft.ML.Data;
using Microsoft.ML.Data.IO;
using Microsoft.ML.Internal.Utilities;
using Microsoft.ML.Runtime;
namespace Microsoft.ML
{
/// <summary>
/// Collection of extension methods for the <see cref="DataOperationsCatalog"/> to read from delimited text
/// files such as csv and tsv.
/// </summary>
public static class TextLoaderSaverCatalog
{
/// <summary>
/// Create a text loader <see cref="TextLoader"/>.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="columns">Array of columns <see cref="TextLoader.Column"/> defining the schema.</param>
/// <param name="separatorChar">The character used as separator between data points in a row. By default the tab character is used as separator.</param>
/// <param name="hasHeader">Whether the file has a header with feature names. When a <see paramref="dataSample"/> is provided, <see langword="true"/>
/// indicates that the first line in the <see paramref="dataSample"/> will be used for feature names, and that when <see cref="TextLoader.Load(IMultiStreamSource)"/>
/// is called, the first line will be skipped. When there is no <see paramref="dataSample"/> provided, <see langword="true"/> just indicates that the loader should
/// skip the first line when <see cref="TextLoader.Load(IMultiStreamSource)"/> is called, but columns will not have slot names annotations. This is
/// because the output schema is made when the loader is created, and not when <see cref="TextLoader.Load(IMultiStreamSource)"/> is called.</param>
/// <param name="dataSample">The optional location of a data sample. The sample can be used to infer slot name annotations if present, and also the number
/// of slots in a column defined with <see cref="TextLoader.Range"/> with <see langword="null"/> maximum index.
/// If the sample has been saved with ML.NET's <see cref="SaveAsText(DataOperationsCatalog, IDataView, Stream, char, bool, bool, bool, bool)"/>,
/// it will also contain the schema information in the header that the loader can read even if <paramref name="columns"/> is <see langword="null"/>.
/// In order to use the schema defined in the file, all other arguments sould be left with their default values.</param>
/// <param name="allowQuoting">Whether the input may include double-quoted values. This parameter is used to distinguish separator characters
/// in an input value from actual separators. When <see langword="true"/>, separators within double quotes are treated as part of the
/// input value. When <see langword="false"/>, all separators, even those within quotes, are treated as delimiting a new column.</param>
/// <param name="trimWhitespace">Remove trailing whitespace from lines.</param>
/// <param name="allowSparse">Whether the input may include sparse representations. For example, a row containing
/// "5 2:6 4:3" means that there are 5 columns, and the only non-zero are columns 2 and 4, which have values 6 and 3,
/// respectively. Column indices are zero-based, so columns 2 and 4 represent the 3rd and 5th columns.
/// A column may also have dense values followed by sparse values represented in this fashion. For example,
/// a row containing "1 2 5 2:6 4:3" represents two dense columns with values 1 and 2, followed by 5 sparsely represented
/// columns with values 0, 0, 6, 0, and 3. The indices of the sparse columns start from 0, even though 0 represents the third column.</param>
/// <example>
/// <format type="text/markdown">
/// <]
/// ]]>
/// </format>
/// </example>
public static TextLoader CreateTextLoader(this DataOperationsCatalog catalog,
TextLoader.Column[] columns,
char separatorChar = TextLoader.Defaults.Separator,
bool hasHeader = TextLoader.Defaults.HasHeader,
IMultiStreamSource dataSample = null,
bool allowQuoting = TextLoader.Defaults.AllowQuoting,
bool trimWhitespace = TextLoader.Defaults.TrimWhitespace,
bool allowSparse = TextLoader.Defaults.AllowSparse)
{
var options = new TextLoader.Options
{
Columns = columns,
Separators = new[] { separatorChar },
HasHeader = hasHeader,
AllowQuoting = allowQuoting,
TrimWhitespace = trimWhitespace,
AllowSparse = allowSparse,
};
return new TextLoader(CatalogUtils.GetEnvironment(catalog), options: options, dataSample: dataSample);
}
/// <summary>
/// Create a text loader <see cref="TextLoader"/>.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="options">Defines the settings of the load operation.</param>
/// <param name="dataSample">The optional location of a data sample. The sample can be used to infer slot name annotations if present, and also the number
/// of slots in <see cref="TextLoader.Options.Columns"/> defined with <see cref="TextLoader.Range"/> with <see langword="null"/> maximum index.
/// If the sample has been saved with ML.NET's <see cref="SaveAsText(DataOperationsCatalog, IDataView, Stream, char, bool, bool, bool, bool)"/>,
/// it will also contain the schema information in the header that the loader can read even if <see cref="TextLoader.Options.Columns"/> are not specified.
/// In order to use the schema defined in the file, all other <see cref="TextLoader.Options"/> sould be left with their default values.</param>
public static TextLoader CreateTextLoader(this DataOperationsCatalog catalog,
TextLoader.Options options,
IMultiStreamSource dataSample = null)
=> new TextLoader(CatalogUtils.GetEnvironment(catalog), options, dataSample);
/// <summary>
/// Create a text loader <see cref="TextLoader"/> by inferencing the dataset schema from a data model type.
/// </summary>
/// <typeparam name="TInput">Defines the schema of the data to be loaded. Use public fields or properties
/// decorated with <see cref="LoadColumnAttribute"/> (and possibly other attributes) to specify the column
/// names and their data types in the schema of the loaded data.</typeparam>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="separatorChar">Column separator character. Default is '\t'</param>
/// <param name="hasHeader">Whether the file has a header with feature names. When a <see paramref="dataSample"/> is provided, <see langword="true"/>
/// indicates that the first line in the <see paramref="dataSample"/> will be used for feature names, and that when <see cref="TextLoader.Load(IMultiStreamSource)"/>
/// is called, the first line will be skipped. When there is no <see paramref="dataSample"/> provided, <see langword="true"/> just indicates that the loader should
/// skip the first line when <see cref="TextLoader.Load(IMultiStreamSource)"/> is called, but columns will not have slot names annotations. This is
/// because the output schema is made when the loader is created, and not when <see cref="TextLoader.Load(IMultiStreamSource)"/> is called.</param>
/// <param name="dataSample">The optional location of a data sample. The sample can be used to infer slot name annotations if present.</param>
/// <param name="allowQuoting">Whether the input may include double-quoted values. This parameter is used to distinguish separator characters
/// in an input value from actual separators. When <see langword="true"/>, separators within double quotes are treated as part of the
/// input value. When <see langword="false"/>, all separators, even those whitin quotes, are treated as delimiting a new column.</param>
/// <param name="trimWhitespace">Remove trailing whitespace from lines.</param>
/// <param name="allowSparse">Whether the input may include sparse representations. For example, a row containing
/// "5 2:6 4:3" means that there are 5 columns, and the only non-zero are columns 2 and 4, which have values 6 and 3,
/// respectively. Column indices are zero-based, so columns 2 and 4 represent the 3rd and 5th columns.
/// A column may also have dense values followed by sparse values represented in this fashion. For example,
/// a row containing "1 2 5 2:6 4:3" represents two dense columns with values 1 and 2, followed by 5 sparsely represented
/// columns with values 0, 0, 6, 0, and 3. The indices of the sparse columns start from 0, even though 0 represents the third column.</param>
public static TextLoader CreateTextLoader<TInput>(this DataOperationsCatalog catalog,
char separatorChar = TextLoader.Defaults.Separator,
bool hasHeader = TextLoader.Defaults.HasHeader,
IMultiStreamSource dataSample = null,
bool allowQuoting = TextLoader.Defaults.AllowQuoting,
bool trimWhitespace = TextLoader.Defaults.TrimWhitespace,
bool allowSparse = TextLoader.Defaults.AllowSparse)
=> TextLoader.CreateTextLoader<TInput>(CatalogUtils.GetEnvironment(catalog), hasHeader, separatorChar, allowQuoting,
allowSparse, trimWhitespace, dataSample: dataSample);
/// <summary>
/// Create a text loader <see cref="TextLoader"/> by inferencing the dataset schema from a data model type.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="options">Defines the settings of the load operation. Defines the settings of the load operation. No need to specify a Columns field,
/// as columns will be infered by this method.</param>
/// <param name="dataSample">The optional location of a data sample. The sample can be used to infer information
/// about the columns, such as slot names.</param>
public static TextLoader CreateTextLoader<TInput>(this DataOperationsCatalog catalog,
TextLoader.Options options,
IMultiStreamSource dataSample = null)
=> TextLoader.CreateTextLoader<TInput>(CatalogUtils.GetEnvironment(catalog), options, dataSample);
/// <summary>
/// Load a <see cref="IDataView"/> from a text file using <see cref="TextLoader"/>.
/// Note that <see cref="IDataView"/>'s are lazy, so no actual loading happens here, just schema validation.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="path">The path to the file(s).</param>
/// <param name="columns">The columns of the schema.</param>
/// <param name="separatorChar">The character used as separator between data points in a row. By default the tab character is used as separator.</param>
/// <param name="hasHeader">Whether the file has a header. When <see langword="true"/>, the loader will skip the first line when
/// <see cref="TextLoader.Load(IMultiStreamSource)"/> is called.</param>
/// <param name="allowQuoting">Whether the input may include double-quoted values. This parameter is used to distinguish separator characters
/// in an input value from actual separators. When <see langword="true"/>, separators within double quotes are treated as part of the
/// input value. When <see langword="false"/>, all separators, even those whitin quotes, are treated as delimiting a new column.
/// It is also used to distinguish empty values from missing values. When <see langword="true"/>, missing value are denoted by consecutive
/// separators and empty values by \"\". When <see langword="false"/>, empty values are denoted by consecutive separators and missing
/// values by the default missing value for each type documented in <see cref="DataKind"/>.</param>
/// <param name="trimWhitespace">Remove trailing whitespace from lines.</param>
/// <param name="allowSparse">Whether the input may include sparse representations. For example, a row containing
/// "5 2:6 4:3" means that there are 5 columns, and the only non-zero are columns 2 and 4, which have values 6 and 3,
/// respectively. Column indices are zero-based, so columns 2 and 4 represent the 3rd and 5th columns.
/// A column may also have dense values followed by sparse values represented in this fashion. For example,
/// a row containing "1 2 5 2:6 4:3" represents two dense columns with values 1 and 2, followed by 5 sparsely represented
/// columns with values 0, 0, 6, 0, and 3. The indices of the sparse columns start from 0, even though 0 represents the third column.</param>
/// <returns>The data view.</returns>
public static IDataView LoadFromTextFile(this DataOperationsCatalog catalog,
string path,
TextLoader.Column[] columns,
char separatorChar = TextLoader.Defaults.Separator,
bool hasHeader = TextLoader.Defaults.HasHeader,
bool allowQuoting = TextLoader.Defaults.AllowQuoting,
bool trimWhitespace = TextLoader.Defaults.TrimWhitespace,
bool allowSparse = TextLoader.Defaults.AllowSparse)
{
CheckValidPathContents(path);
var options = new TextLoader.Options
{
Columns = columns,
Separators = new[] { separatorChar },
HasHeader = hasHeader,
AllowQuoting = allowQuoting,
TrimWhitespace = trimWhitespace,
AllowSparse = allowSparse
};
var loader = new TextLoader(CatalogUtils.GetEnvironment(catalog), options: options);
return loader.Load(new MultiFileSource(path));
}
/// <summary>
/// Load a <see cref="IDataView"/> from a text file using <see cref="TextLoader"/>.
/// Note that <see cref="IDataView"/>'s are lazy, so no actual loading happens here, just schema validation.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="path">Specifies a file or path of files from which to load.</param>
/// <param name="options">Defines the settings of the load operation.</param>
/// <example>
/// <format type="text/markdown">
/// <]
/// ]]>
/// </format>
/// </example>
public static IDataView LoadFromTextFile(this DataOperationsCatalog catalog, string path,
TextLoader.Options options = null)
{
CheckValidPathContents(path);
var env = catalog.GetEnvironment();
var source = new MultiFileSource(path);
return new TextLoader(env, options, dataSample: source).Load(source);
}
/// <summary>
/// Load a <see cref="IDataView"/> from a text file using <see cref="TextLoader"/>.
/// Note that <see cref="IDataView"/>'s are lazy, so no actual loading happens here, just schema validation.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="path">The path to the file(s).</param>
/// <param name="separatorChar">Column separator character. Default is '\t'</param>
/// <param name="hasHeader">Whether the file has a header. When <see langword="true"/>, the loader will skip the first line when
/// <see cref="TextLoader.Load(IMultiStreamSource)"/> is called.</param>
/// <param name="allowQuoting">Whether the input may include double-quoted values. This parameter is used to distinguish separator characters
/// in an input value from actual separators. When <see langword="true"/>, separators within double quotes are treated as part of the
/// input value. When <see langword="false"/>, all separators, even those whitin quotes, are treated as delimiting a new column.
/// It is also used to distinguish empty values from missing values. When <see langword="true"/>, missing value are denoted by consecutive
/// separators and empty values by \"\". When <see langword="false"/>, empty values are denoted by consecutive separators and missing
/// values by the default missing value for each type documented in <see cref="DataKind"/>.</param>
/// <param name="trimWhitespace">Remove trailing whitespace from lines.</param>
/// <param name="allowSparse">Whether the input may include sparse representations. For example, a row containing
/// "5 2:6 4:3" means that there are 5 columns, and the only non-zero are columns 2 and 4, which have values 6 and 3,
/// respectively. Column indices are zero-based, so columns 2 and 4 represent the 3rd and 5th columns.
/// A column may also have dense values followed by sparse values represented in this fashion. For example,
/// a row containing "1 2 5 2:6 4:3" represents two dense columns with values 1 and 2, followed by 5 sparsely represented
/// columns with values 0, 0, 6, 0, and 3. The indices of the sparse columns start from 0, even though 0 represents the third column.</param>
/// <returns>The data view.</returns>
public static IDataView LoadFromTextFile<TInput>(this DataOperationsCatalog catalog,
string path,
char separatorChar = TextLoader.Defaults.Separator,
bool hasHeader = TextLoader.Defaults.HasHeader,
bool allowQuoting = TextLoader.Defaults.AllowQuoting,
bool trimWhitespace = TextLoader.Defaults.TrimWhitespace,
bool allowSparse = TextLoader.Defaults.AllowSparse)
{
CheckValidPathContents(path);
// REVIEW: it is almost always a mistake to have a 'trainable' text loader here.
// Therefore, we are going to disallow data sample.
return TextLoader.CreateTextLoader<TInput>(CatalogUtils.GetEnvironment(catalog), hasHeader, separatorChar,
allowQuoting, allowSparse, trimWhitespace).Load(new MultiFileSource(path));
}
/// <summary>
/// Load a <see cref="IDataView"/> from a text file using <see cref="TextLoader"/>.
/// Note that <see cref="IDataView"/>'s are lazy, so no actual loading happens here, just schema validation.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="path">Specifies a file or path of files from which to load.</param>
/// <param name="options">Defines the settings of the load operation. No need to specify a Columns field,
/// as columns will be infered by this method.</param>
/// <returns>The data view.</returns>
public static IDataView LoadFromTextFile<TInput>(this DataOperationsCatalog catalog, string path,
TextLoader.Options options)
{
CheckValidPathContents(path);
return TextLoader.CreateTextLoader<TInput>(CatalogUtils.GetEnvironment(catalog), options)
.Load(new MultiFileSource(path));
}
/// <summary>
/// Save the <see cref="IDataView"/> as text.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="data">The data view to save.</param>
/// <param name="stream">The stream to write to.</param>
/// <param name="separatorChar">The column separator.</param>
/// <param name="headerRow">Whether to write the header row.</param>
/// <param name="schema">Whether to write the header comment with the schema.</param>
/// <param name="keepHidden">Whether to keep hidden columns in the dataset.</param>
/// <param name="forceDense">Whether to save columns in dense format even if they are sparse vectors.</param>
/// <example>
/// <format type="text/markdown">
/// <]
/// ]]>
/// </format>
/// </example>
public static void SaveAsText(this DataOperationsCatalog catalog,
IDataView data,
Stream stream,
char separatorChar = TextSaver.Defaults.Separator,
bool headerRow = TextSaver.Defaults.OutputHeader,
bool schema = TextSaver.Defaults.OutputSchema,
bool keepHidden = false,
bool forceDense = TextSaver.Defaults.ForceDense)
{
Contracts.CheckValue(catalog, nameof(catalog));
Contracts.CheckValue(data, nameof(data));
Contracts.CheckValue(stream, nameof(stream));
var env = catalog.GetEnvironment();
var saver = new TextSaver(env, new TextSaver.Arguments { Dense = forceDense, Separator = separatorChar.ToString(), OutputHeader = headerRow, OutputSchema = schema });
using (var ch = env.Start("Saving data"))
DataSaverUtils.SaveDataView(ch, saver, data, stream, keepHidden);
}
/// <summary>
/// Checks the validity of a given path, and whether or not it is a
/// valid path to a data file, or a path to a directory of files.
/// </summary>
/// <param name="path">Specifies a file or path of files from which to load.</param>
private static void CheckValidPathContents(string path)
{
Contracts.CheckNonEmpty(path, nameof(path));
if (!File.Exists(path) && StreamUtils.ExpandWildCards(path).Length < 1)
throw Contracts.ExceptParam(nameof(path), "File or directory does not exist at path: {0}", path);
}
}
}
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