以下代码执行请求的任务。定义了一个用户定义的函数,该函数接收 a 的两列DataFrame
作为参数。因此,对于每一行,搜索项目是否在项目列表中。如果找到该项目,则返回 1,否则返回 0。
# Imports
from pyspark.sql.types import IntegerType
from pyspark.sql.functions import udf
# First we create a RDD in order to create a dataFrame:
rdd = sc.parallelize([('u1', 1, [1 ,2, 3]), ('u1', 4, [1, 2, 3])])
df = rdd.toDF(['user', 'item', 'fav_items'])
# Print dataFrame
df.show()
# We make an user define function that receives two columns and do operation
function = udf(lambda item, items: 1 if item in items else 0, IntegerType())
df.select('user', 'item', 'fav_items', function(col('item'), col('fav_items')).alias('result')).show()
结果如下:
+----+----+---------+
|user|item|fav_items|
+----+----+---------+
| u1| 1|[1, 2, 3]|
| u1| 4|[1, 2, 3]|
+----+----+---------+
+----+----+---------+------+
|user|item|fav_items|result|
+----+----+---------+------+
| u1| 1|[1, 2, 3]| 1|
| u1| 4|[1, 2, 3]| 0|
+----+----+---------+------+