Dataframe Spark-将包含JSON字符串的coulmn从StringType转换为ArrayType（StringType（））

我有一个dataframe df，它包含json字符串，如下所示

'''[{"@id":"Party_1","@ObjectID":"Policy_1"},{"@id":"Party_2","@ObjectID":"Policy_2"},{"@id":"Party_3","@ObjectID":"Policy_3"}]'''

df模式：

root
 |-- col1: string (nullable = true)

如何将其转换为字符串数组（ArrayType（StringType（））

结果应该是

['{"@id":"Party_1","@OriginatingObjectID":"Policy_1"}',
 '{"@id":"Party_2","@OriginatingObjectID":"Policy_2"}',
 '{"@id":"Party_3","@OriginatingObjectID":"Policy_3"}']

结果架构：

root
 |-- arr_col: array (nullable = true)
 |          |-- element: string (containsNull = true)

---

任何帮助都将不胜感激。谢谢大家!

您可以使用from_json函数获取json字段，只需稍微修改以下值

data = [
    ('[{"@id":"Party_1","@ObjectID":"Policy_1"},{"@id":"Party_2","@ObjectID":"Policy_2"},{"@id":"Party_3","@ObjectID":"Policy_3"}]', 2767),
    ('[{"@id":"Party_1","@ObjectID":"Policy_1"},{"@id":"Party_2","@ObjectID":"Policy_2"},{"@id":"Party_3","@ObjectID":"Policy_3"}]', 4235)
]

df = spark.createDataFrame(data).toDF(*["value", "count"])\
    .withColumn("value", f.regexp_replace(f.col("value"), "\\[\\{", "{\"arr\": [{"))\
    .withColumn("value", f.regexp_replace(f.col("value"), "\\}\\]", "}]}"))


json_schema = spark.read.json(df.rdd.map(lambda row: row.value)).schema
resultDF = df.select(f.from_json("value", 
schema=json_schema).alias("array_col"))\
    .select("array_col.*")

resultDF.printSchema()
resultDF.show(truncate=False)

如果希望嵌套json作为字符串，也可以使用自定义模式

输出架构：

root
 |-- arr: array (nullable = true)
 |    |-- element: struct (containsNull = true)
 |    |    |-- @ObjectID: string (nullable = true)
 |    |    |-- @id: string (nullable = true)

输出：

+---------------------------------------------------------------+
|arr                                                            |
+---------------------------------------------------------------+
|[{Policy_1, Party_1}, {Policy_2, Party_2}, {Policy_3, Party_3}]|
|[{Policy_1, Party_1}, {Policy_2, Party_2}, {Policy_3, Party_3}]|
+---------------------------------------------------------------+

---

您的“预期结果”没有您正在描述的架构。您期望的结果是ArrayType（MapType（StringType（）））。请更清楚地说明您的期望。对不起，我已经更新了结果。预期结果是JSON字符串数组。