我在 spark 数据框中有一列“true_recoms”：
-RECORD 17-----------------------------------------------------------------
item | 20380109
true_recoms | {"5556867":1,"5801144":5,"7397596":21}
我需要“爆炸”这个列来得到这样的东西：
item | 20380109
recom_item | 5556867
recom_cnt | 1
..............
item | 20380109
recom_item | 5801144
recom_cnt | 5
..............
item | 20380109
recom_item | 7397596
recom_cnt | 21
我试过使用 from_json 但它不起作用：
schema_json = StructType(fields=[
StructField("item", StringType()),
StructField("recoms", StringType())
])
df.select(col("true_recoms"),from_json(col("true_recoms"), schema_json)).show(5)
+--------+--------------------+------+
| item| true_recoms|true_r|
+--------+--------------------+------+
|31746548|{"32731749":3,"31...| [,]|
|17359322|{"17359392":1,"17...| [,]|
|31480894|{"31480598":1,"31...| [,]|
| 7265665|{"7265891":1,"503...| [,]|
|31350949|{"32218698":1,"31...| [,]|
+--------+--------------------+------+
only showing top 5 rows