什么是错,此代码试图改变一个datetime列的一天pyspark变化一天datetime列
import pyspark
import pyspark.sql.functions as sf
import pyspark.sql.types as sparktypes
import datetime
sc = pyspark.SparkContext(appName="test")
sqlcontext = pyspark.SQLContext(sc)
rdd = sc.parallelize([('a',datetime.datetime(2014, 1, 9, 0, 0)),
('b',datetime.datetime(2014, 1, 27, 0, 0)),
('c',datetime.datetime(2014, 1, 31, 0, 0))])
testdf = sqlcontext.createDataFrame(rdd, ["id", "date"])
print(testdf.show())
print(testdf.printSchema())
给出了测试数据框:
+---+--------------------+
| id| date|
+---+--------------------+
| a|2014-01-09 00:00:...|
| b|2014-01-27 00:00:...|
| c|2014-01-31 00:00:...|
+---+--------------------+
root
|-- id: string (nullable = true)
|-- date: timestamp (nullable = true)
然后我定义一个UDF改变天日期栏:
def change_day_(date, day):
return date.replace(day=day)
change_day = sf.udf(change_day_, sparktypes.TimestampType())
testdf.withColumn("PaidMonth", change_day(testdf.date, 1)).show(1)
这就提出了一个错误:
Py4JError: An error occurred while calling z:org.apache.spark.sql.functions.col. Trace:
py4j.Py4JException: Method col([class java.lang.Integer]) does not exist
at py4j.reflection.ReflectionEngine.getMethod(ReflectionEngine.java:318)
at py4j.reflection.ReflectionEngine.getMethod(ReflectionEngine.java:339)
at py4j.Gateway.invoke(Gateway.java:274)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:214)
at java.lang.Thread.run(Thread.java:745)
也许尝试用'lit(1)'替换'1'(在调用'change_day')后,'从pyspark.sql.functions导入点亮'后执行'? –
谢谢!这工作! – muon
@ArthurTacca你能解释一下为什么? – muon