如何将结构或类的数组从UDF返回到数据框列值? [英] How to return an array of struct or class from UDF into dataframe column value?
问题描述
d = [{'ID': '1', 'pID': 1000, 'startTime':'2018.07.02T03:34:20', 'endTime':'2018.07.03T02:40:20'}, {'ID': '1', 'pID': 1000, 'startTime':'2018.07.02T03:45:20', 'endTime':'2018.07.03T02:50:20'}, {'ID': '2', 'pID': 2000, 'startTime':'2018.07.02T03:34:20', 'endTime':'2018.07.03T02:40:20'}, {'ID': '2', 'pID': 2000, 'startTime':'2018.07.02T03:45:20', 'endTime':'2018.07.03T02:50:20'}]
df = spark.createDataFrame(d)
Dates = namedtuple("Dates", "startTime endTime")
def MergeAdjacentUsage(timeSets):
DatesArray = []
for times in timeSets:
DatesArray.append(Dates(startTime=times.startTime, endTime=times.endTime))
return DatesArray
MergeAdjacentUsages = udf(MergeAdjacentUsage,ArrayType(Dates()))
df1=df.groupBy(['ID','pID']).agg(MergeAdjacentUsages(F.collect_list(struct('startTime','endTime'))).alias("Times"))
display(df1)
我想要的只是设置colum UDF返回的结构数组的n值。它给我的错误是:
All I want is to set column value to an array of stuct that is returned by UDF. It is giving me error as:
TypeError: new ()恰好接受3个参数(给定1个)
TypeError: new() takes exactly 3 arguments (1 given)
TypeError Traceback(最近一次调用
最后)在()
22返回DatesArray
23
---> 24 MergeAdjacentUsages = udf(MergeAdjacentUsage,ArrayType(Dates()))
25
26 df1 = df.groupBy(['ID','pID'])。agg(MergeAdjacentUsages(F.collect_list(struct( 'startTime','endTime')))。alias( Times))
TypeError Traceback (most recent call last) in () 22 return DatesArray 23 ---> 24 MergeAdjacentUsages = udf(MergeAdjacentUsage,ArrayType(Dates())) 25 26 df1=df.groupBy(['ID','pID']).agg(MergeAdjacentUsages(F.collect_list(struct('startTime','endTime'))).alias("Times"))
任何帮助,想法或提示将不胜感激
Any help, idea or hint will be appreciated.
推荐答案
pyspark不允许用户定义的Class对象作为Dataframe列类型。相反,我们需要创建 StructType
,其用法类似于python中的类/命名元组。
pyspark does not let user defined Class objects as Dataframe Column Types. Instead we need to create the StructType
which can be used similar to a class / named tuple in python.
例如:
from pyspark.sql.types import *
from pyspark.sql.functions import udf
from pyspark.sql import functions as F
# from pyspark.sql.functions import *
d = [{'ID': '1', 'pID': 1000, 'startTime': '2018.07.02T03:34:20', 'endTime': '2018.07.03T02:40:20'},
{'ID': '1', 'pID': 1000, 'startTime': '2018.07.02T03:45:20', 'endTime': '2018.07.03T02:50:20'},
{'ID': '2', 'pID': 2000, 'startTime': '2018.07.02T03:34:20', 'endTime': '2018.07.03T02:40:20'},
{'ID': '2', 'pID': 2000, 'startTime': '2018.07.02T03:45:20', 'endTime': '2018.07.03T02:50:20'}]
df = spark.createDataFrame(d)
# Dates = namedtuple("Dates", "startTime endTime")
schema = ArrayType(StructType([
StructField("startTime", StringType(), False),
StructField("endTime", StringType(), False)
]))
MergeAdjacentUsages = udf(lambda xs: xs, schema)
df1 = df.groupBy(['ID', 'pID']).agg(MergeAdjacentUsages(
F.collect_list(F.struct('startTime', 'endTime'))).alias("Times"))
df1.show(truncate=False)
+---+----+----------------------------------------------------------------------------------------+
|ID |pID |Times |
+---+----+----------------------------------------------------------------------------------------+
|2 |2000|[[2018.07.02T03:34:20, 2018.07.03T02:40:20], [2018.07.02T03:45:20, 2018.07.03T02:50:20]]|
|1 |1000|[[2018.07.02T03:34:20, 2018.07.03T02:40:20], [2018.07.02T03:45:20, 2018.07.03T02:50:20]]|
+---+----+----------------------------------------------------------------------------------------+
希望这会有所帮助!
这篇关于如何将结构或类的数组从UDF返回到数据框列值?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!