相关疑难解决方法(0)

我在这里看到了一个解决方案但是当我尝试它时对我不起作用.

首先我导入cars.csv文件:

val df = sqlContext.read
              .format("com.databricks.spark.csv")
              .option("header", "true")
              .load("/usr/local/spark/cars.csv")

如下所示:

+----+-----+-----+--------------------+-----+
|year| make|model|             comment|blank|
+----+-----+-----+--------------------+-----+
|2012|Tesla|    S|          No comment|     |
|1997| Ford| E350|Go get one now th...|     |
|2015|Chevy| Volt|                null| null|

然后我这样做:

df.na.fill("e",Seq("blank"))

但是空值没有改变.

谁能帮我 ？

我想删除字符串从col1存在于col2:

val df = spark.createDataFrame(Seq(
("Hi I heard about Spark", "Spark"),
("I wish Java could use case classes", "Java"),
("Logistic regression models are neat", "models")
)).toDF("sentence", "label")

使用regexp_replace或translateref:spark函数api

val res = df.withColumn("sentence_without_label", regexp_replace 
(col("sentence") , "(?????)", "" ))

所以res看起来如下: