com.johnsnowlabs.nlp.MultiDocumentAssembler.scala Maven / Gradle / Ivy
/*
* Copyright 2017-2022 John Snow Labs
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.johnsnowlabs.nlp
import org.apache.spark.ml.Transformer
import org.apache.spark.ml.param.{Param, ParamMap, StringArrayParam}
import org.apache.spark.ml.util.{DefaultParamsReadable, DefaultParamsWritable, Identifiable}
import org.apache.spark.sql.expressions.UserDefinedFunction
import org.apache.spark.sql.functions.udf
import org.apache.spark.sql.types._
import org.apache.spark.sql.{DataFrame, Dataset, Row}
import com.johnsnowlabs.nlp.AnnotatorType._
/** Prepares data into a format that is processable by Spark NLP. This is the entry point for
* every Spark NLP pipeline. The `MultiDocumentAssembler` can read either a `String` column or an
* `Array[String]`. Additionally, [[MultiDocumentAssembler.setCleanupMode]] can be used to
* pre-process the text (Default: `disabled`). For possible options please refer the parameters
* section.
*
* For more extended examples on document pre-processing see the
* [[https://github.com/JohnSnowLabs/spark-nlp-workshop/blob/master/tutorials/Certification_Trainings/Public/2.Text_Preprocessing_with_SparkNLP_Annotators_Transformers.ipynb Spark NLP Workshop]].
*
* ==Example==
* {{{
* import spark.implicits._
* import com.johnsnowlabs.nlp.MultiDocumentAssembler
*
* val data = Seq("Spark NLP is an open-source text processing library.").toDF("text")
* val multiDocumentAssembler = new MultiDocumentAssembler().setInputCols("text").setOutputCols("document")
*
* val result = multiDocumentAssembler.transform(data)
*
* result.select("document").show(false)
* +----------------------------------------------------------------------------------------------+
* |document |
* +----------------------------------------------------------------------------------------------+
* |[[document, 0, 51, Spark NLP is an open-source text processing library., [sentence -> 0], []]]|
* +----------------------------------------------------------------------------------------------+
*
* result.select("document").printSchema
* root
* |-- document: array (nullable = true)
* | |-- element: struct (containsNull = true)
* | | |-- annotatorType: string (nullable = true)
* | | |-- begin: integer (nullable = false)
* | | |-- end: integer (nullable = false)
* | | |-- result: string (nullable = true)
* | | |-- metadata: map (nullable = true)
* | | | |-- key: string
* | | | |-- value: string (valueContainsNull = true)
* | | |-- embeddings: array (nullable = true)
* | | | |-- element: float (containsNull = false)
* }}}
*
* @param uid
* required uid for storing annotator to disk
* @groupname anno Annotator types
* @groupdesc anno
* Required input and expected output annotator types
* @groupname Ungrouped Members
* @groupname param Parameters
* @groupname setParam Parameter setters
* @groupname getParam Parameter getters
* @groupname Ungrouped Members
* @groupprio param 1
* @groupprio anno 2
* @groupprio Ungrouped 3
* @groupprio setParam 4
* @groupprio getParam 5
* @groupdesc param
* A list of (hyper-)parameter keys this annotator can take. Users can set and get the
* parameter values through setters and getters, respectively.
*/
class MultiDocumentAssembler(override val uid: String)
extends Transformer
with DefaultParamsWritable
with HasOutputAnnotatorType {
def this() = this(Identifiable.randomUID("MultiDocumentAssembler"))
/** Output Annotator Type: DOCUMENT
*
* @group anno
*/
override val outputAnnotatorType: AnnotatorType = DOCUMENT
override def copy(extra: ParamMap): Transformer = defaultCopy(extra)
private type DocumentationContent = Row
val EMPTY_STR = ""
/** Name of input annotation cols
*
* @group param
*/
val inputCols: StringArrayParam =
new StringArrayParam(this, "inputCols", "Name of input annotation cols")
/** @group setParam */
def setInputCols(value: Array[String]): this.type = set(inputCols, value)
/** @group setParam */
def setInputCols(value: String*): this.type = setInputCols(value.toArray)
/** @group getParam */
def getInputCols: Array[String] = $(inputCols)
/** @group param */
val outputCols: StringArrayParam =
new StringArrayParam(this, "outputCols", "Name of output cols")
/** @group setParam */
def setOutputCols(value: Array[String]): this.type = set(outputCols, value)
/** @group setParam */
def setOutputCols(value: String*): this.type = setOutputCols(value.toArray)
/** @group getParam */
def getOutputCols: Array[String] = get(outputCols).getOrElse(getInputCols.map("finished_" + _))
/** Id column for row reference
*
* @group param
*/
val idCol: Param[String] = new Param[String](this, "idCol", "id column for row reference")
/** Metadata for document column
*
* @group param
*/
val metadataCol: Param[String] =
new Param[String](this, "metadataCol", "metadata for document column")
/** cleanupMode can take the following values:
* - `disabled`: keep original. Useful if need to head back to source later
* - `inplace`: newlines and tabs into whitespaces, not stringified ones, don't trim
* - `inplace_full`: newlines and tabs into whitespaces, including stringified, don't trim
* - `shrink`: all whitespaces, newlines and tabs to a single whitespace, but not
* stringified, do trim
* - `shrink_full`: all whitespaces, newlines and tabs to a single whitespace, stringified
* ones too, trim all
* - `each`: newlines and tabs to one whitespace each
* - `each_full`: newlines and tabs, stringified ones too, to one whitespace each
* - `delete_full`: remove stringified newlines and tabs (replace with nothing)
*
* @group param
*/
val cleanupMode: Param[String] = new Param[String](
this,
"cleanupMode",
"possible values: " +
"disabled, inplace, inplace_full, shrink, shrink_full, each, each_full, delete_full")
setDefault(cleanupMode -> "disabled")
/** Id column for row reference
*
* @group setParam
*/
def setIdCol(value: String): this.type = set(idCol, value)
/** Id column for row reference
*
* @group getParam
*/
def getIdCol: String = $(idCol)
/** Metadata for document column
*
* @group setParam
*/
def setMetadataCol(value: String): this.type = set(metadataCol, value)
/** cleanupMode to pre-process text
*
* @group setParam
*/
def setCleanupMode(v: String): this.type = {
v.trim.toLowerCase() match {
case "disabled" => set(cleanupMode, "disabled")
case "inplace" => set(cleanupMode, "inplace")
case "inplace_full" => set(cleanupMode, "inplace_full")
case "shrink" => set(cleanupMode, "shrink")
case "shrink_full" => set(cleanupMode, "shrink_full")
case "each" => set(cleanupMode, "each")
case "each_full" => set(cleanupMode, "each_full")
case "delete_full" => set(cleanupMode, "delete_full")
case b =>
throw new IllegalArgumentException(s"Special Character Cleanup supports only: " +
s"disabled, inplace, inplace_full, shrink, shrink_full, each, each_full, delete_full. Received: $b")
}
}
/** cleanupMode to pre-process text
*
* @group getParam
*/
def getCleanupMode: String = $(cleanupMode)
/** Metadata for document column
*
* @group getParam
*/
def getMetadataCol: String = $(metadataCol)
private[nlp] def assemble(text: String, metadata: Map[String, String]): Seq[Annotation] = {
val _text = Option(text).getOrElse(EMPTY_STR)
val possiblyCleaned = $(cleanupMode) match {
case "disabled" => _text
case "inplace" => _text.replaceAll("\\s", " ")
case "inplace_full" => _text.replaceAll("\\s|(?:\\\\r)?(?:\\\\n)|(?:\\\\t)", " ")
case "shrink" => _text.trim.replaceAll("\\s+", " ")
case "shrink_full" => _text.trim.replaceAll("\\s+|(?:\\\\r)*(?:\\\\n)+|(?:\\\\t)+", " ")
case "each" => _text.replaceAll("\\s[\\n\\t]", " ")
case "each_full" => _text.replaceAll("\\s(?:\\n|\\t|(?:\\\\r)?(?:\\\\n)|(?:\\\\t))", " ")
case "delete_full" => _text.trim.replaceAll("(?:\\\\r)?(?:\\\\n)|(?:\\\\t)", "")
case b =>
throw new IllegalArgumentException(s"Special Character Cleanup supports only: " +
s"disabled, inplace, inplace_full, shrink, shrink_full, each, each_full, delete_full. Received: $b")
}
try {
Seq(
Annotation(outputAnnotatorType, 0, possiblyCleaned.length - 1, possiblyCleaned, metadata))
} catch {
case _: Exception =>
/*
* when there is a null in the row
* it outputs an empty Annotation
* */
Seq.empty[Annotation]
}
}
private[nlp] def assembleFromArray(texts: Seq[String]): Seq[Annotation] = {
texts.zipWithIndex.flatMap { case (text, idx) =>
assemble(text, Map("sentence" -> idx.toString))
}
}
private def dfAssemble: UserDefinedFunction = udf {
(text: String, id: String, metadata: Map[String, String]) =>
assemble(text, metadata ++ Map("id" -> id, "sentence" -> "0"))
}
private def dfAssembleOnlyId: UserDefinedFunction = udf { (text: String, id: String) =>
assemble(text, Map("id" -> id, "sentence" -> "0"))
}
private def dfAssembleNoId: UserDefinedFunction = udf {
(text: String, metadata: Map[String, String]) =>
assemble(text, metadata ++ Map("sentence" -> "0"))
}
private def dfAssembleNoExtras: UserDefinedFunction = udf { text: String =>
assemble(text, Map("sentence" -> "0"))
}
private def dfAssemblyFromArray: UserDefinedFunction = udf { texts: Seq[String] =>
assembleFromArray(texts)
}
/** requirement for pipeline transformation validation. It is called on fit() */
override final def transformSchema(schema: StructType): StructType = {
val metadataBuilder: MetadataBuilder = new MetadataBuilder()
metadataBuilder.putString("annotatorType", outputAnnotatorType)
val outputColsStructure = getOutputCols.map(outpuCol =>
StructField(
outpuCol,
ArrayType(Annotation.dataType),
nullable = false,
metadataBuilder.build))
val outputFields = schema.fields ++ outputColsStructure
StructType(outputFields)
}
override def transform(dataset: Dataset[_]): DataFrame = {
val metadataBuilder: MetadataBuilder = new MetadataBuilder()
metadataBuilder.putString("annotatorType", outputAnnotatorType)
require(
getInputCols.length == getOutputCols.length,
"inputCols and outputCols length must match")
val cols = getInputCols.zip(getOutputCols)
var flattened = dataset
cols.foreach { case (inputCol, outputCol) =>
flattened = {
val documentAnnotations =
if (flattened.schema.fields
.find(_.name == inputCol)
.getOrElse(throw new IllegalArgumentException(
s"Dataset does not have any '$inputCol' column"))
.dataType == ArrayType(StringType, containsNull = false))
dfAssemblyFromArray(flattened.col(inputCol))
else if (get(idCol).isDefined && get(metadataCol).isDefined)
dfAssemble(
flattened.col(inputCol),
flattened.col(getIdCol),
flattened.col(getMetadataCol))
else if (get(idCol).isDefined)
dfAssembleOnlyId(flattened.col(inputCol), flattened.col(getIdCol))
else if (get(metadataCol).isDefined)
dfAssembleNoId(flattened.col(inputCol), flattened.col(getMetadataCol))
else
dfAssembleNoExtras(flattened.col(inputCol))
flattened.withColumn(outputCol, documentAnnotations.as(outputCol, metadataBuilder.build))
}
}
flattened.toDF()
}
}
/** This is the companion object of [[MultiDocumentAssembler]]. Please refer to that class for the
* documentation.
*/
object MultiDocumentAssembler extends DefaultParamsReadable[MultiDocumentAssembler]
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