访问WrappedArray元素 [英] Access to WrappedArray elements

问题描述

我有一个火花数据框，这是模式:

I have a spark dataframe and here is the schema:

|-- eid: long (nullable = true)
|-- age: long (nullable = true)
|-- sex: long (nullable = true)
|-- father: array (nullable = true)
|    |-- element: array (containsNull = true)
|    |    |-- element: long (containsNull = true)

和行示例:.

df.select(df['father']).show()
+--------------------+
|              father|
+--------------------+
|[WrappedArray(-17...|
|[WrappedArray(-11...|
|[WrappedArray(13,...|
+--------------------+

，类型是

DataFrame[father: array<array<bigint>>]

如何访问内部数组的每个元素?例如第一行的-17?我尝试了类似 df.select(df ['father'])(0)(0).show()之类的方法，但是没有运气.

How can I have access to each element of inner array? For example -17 in the first row? I tried different things like df.select(df['father'])(0)(0).show() but no luck.

推荐答案

如果我没记错的话，Python中的语法是

If I'm not mistaken, the syntax for in Python is

df.select(df['father'])[0][0].show()

或

df.select(df['father']).getItem(0).getItem(0).show()

在此处查看一些示例:

See some examples here: http://spark.apache.org/docs/latest/api/python/pyspark.sql.html?highlight=column#pyspark.sql.Column

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