在spark数据框之间的联接中包含列时出错

问题描述

我使用array_contains在 cleanDF 和 sentiment_df 之间进行了联接，效果很好()以包含 cleanDF 中的 Year 列:

I add a .select (36132322) to include the column Year from cleanDF:

Result1 = cleanDF.alias('a').join(sentiment_df.alias('b'), expr("""array_contains(a.MeaningfulWords,b.word)"""), how='left')\
                .select(col('a.ID'),col('a.Year'),col('a.MeaningfulWords'),col('b.word'),col('b.score'))\
                .groupBy("ID")\
                .agg(first("a.MeaningfulWords").alias("MeaningfulWords")\
                  ,collect_list("score").alias("ScoreList")\
                  ,mean("score").alias("MeanScore"))

但是我进入 Result1 与**Result**相同的列:

But I get in Result1 the same columns than **Result**:

display(Result1)

#DataFrame[ID: string, MeaningfulWords: array<string>, ScoreList: array<double>, MeanScore: double]

当我尝试在.agg函数中包含 Year 时:

When I'm try include Year in .agg function:

Result2 = cleanDF.join(sentiment_df, expr("""array_contains(MeaningfulWords,word)"""), how='left')\
                .groupBy("ID")\
                .agg(first("MeaningfulWords").alias("MeaningfulWords"),first("Year").alias("Year")\
                  ,collect_list("score").alias("ScoreList")\
                  ,mean("score").alias("MeanScore"))

Result2.show()

Py4JJavaError: An error occurred while calling o3205.showString.
: org.apache.spark.SparkException: Exception thrown in awaitResult:
    at org.apache.spark.util.ThreadUtils$.awaitResult(ThreadUtils.scala:226)
    at org.apache.spark.sql.execution.exchange.BroadcastExchangeExec.doExecuteBroadcast(BroadcastExchangeExec.scala:146)
    at org.apache.spark.sql.execution.SparkPlan$$anonfun$executeBroadcast$1.apply(SparkPlan.scala:144)
    at org.apache.spark.sql.execution.SparkPlan$$anonfun$executeBroadcast$1.apply(SparkPlan.scala:140)
    at org.apache.spark.sql.execution.SparkPlan$$anonfun$executeQuery$1.apply(SparkPlan.scala:155)
    at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:151)
    at org.apache.spark.sql.execution.SparkPlan.executeQuery(SparkPlan.scala:152)
    at org.apache.spark.sql.execution.SparkPlan.executeBroadcast(SparkPlan.scala:140)
    at org.apache.spark.sql.execution.joins.BroadcastNestedLoopJoinExec.doExecute(BroadcastNestedLoopJoinExec.scala:343)
    ...
    ...
    ...
        Caused by: org.apache.spark.SparkException: Failed to execute user defined function($anonfun$createTransformFunc$1: (string) => array<string>)
            at org.apache.spark.sql.catalyst.expressions.ScalaUDF.eval(ScalaUDF.scala:1066)
            at org.apache.spark.sql.catalyst.expressions.ScalaUDF$$anonfun$2.apply(ScalaUDF.scala:109)
            at org.apache.spark.sql.catalyst.expressions.ScalaUDF$$anonfun$2.apply(ScalaUDF.scala:107)
            at org.apache.spark.sql.catalyst.expressions.ScalaUDF.eval(ScalaUDF.scala:1063)
    ...
    ...
    Caused by: org.apache.spark.SparkException: Job aborted due to stage failure: Task 2 in stage 411.0 failed 1 times, most recent failure: Lost task 2.0 in stage 411.0 (TID 9719, localhost, executor driver): org.apache.spark.SparkException: Failed to execute user defined function($anonfun$5: (array<string>) => array<string>)
        at org.apache.spark.sql.catalyst.expressions.ScalaUDF.eval(ScalaUDF.scala:1066)
        at org.apache.spark.sql.catalyst.expressions.SimpleHigherOrderFunction$class.eval(higherOrderFunctions.scala:208)
        at org.apache.spark.sql.catalyst.expressions.ArrayFilter.eval(higherOrderFunctions.scala:296)
        at org.apache.spark.sql.catalyst.expressions.GeneratedClass$SpecificUnsafeProjection.apply(Unknown Source)
        at org.apache.spark.sql.catalyst.expressions.GeneratedClass$SpecificUnsafeProjection.apply(Unknown Source)
    ...
    ...
    ... 20 more
    Caused by: java.lang.NullPointerException

我在Spark 2.4.5上使用pyspark.

Im using pyspark on spark 2.4.5.

预先感谢您的帮助.

推荐答案

年份"列可能具有空值&因此，它失败并出现Caused by: java.lang.NullPointerException异常.过滤Year列中的所有空值.

Year column might be having null values & because of that it is failing with Caused by: java.lang.NullPointerException exception. Filter all null values from Year column.

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