如何在pyspark的结构内部分解结构中的内部数组/

Question

我是新手。我试过在struct内部爆炸array。JSON循环有点复杂，如下所示。在

{
"id": 1,
"firstfield": "abc",
"secondfield": "zxc",
"firststruct": {
    "secondstruct": {
        "firstarray": [{
            "firstarrayfirstfield": "asd",
            "firstarraysecondfield": "dasd",
            "secondarray": [{
                "score": " 7 "
            }]
        }]
    }
}

}

我试图访问secondarray字段下的score字段，以便能够计算很少的指标并得出每个id的平均分数。在

Answer 1

如果使用Glue，则应将DynamicFrame转换为Spark的DataFrame，然后使用explode函数：

from pyspark.sql.functions import col, explode

scoresDf = dynamicFrame.toDF
  .withColumn("firstExplode", explode(col("firststruct.secondstruct.firstarray")))
  .withColumn("secondExplode", explode(col("firstExplode.secondarray")))
  .select("secondExplode.score") 

scoresDyf = DynamicFrame.fromDF(scoresDf, glueContext, "scoresDyf")