df.na.fill("All Null values become this string")
df.na.fill(5,Seq("StockCode","InvoiceNo"))
val fillColValues=Map("StockCode" -> 5,"Description" -> "No value")
df.na.fill(fillColValues)
df.na.fill("All Null values become this string")
df.na.fill(5,Seq("StockCode","InvoiceNo"))
val fillColValues=Map("StockCode" -> 5,"Description" -> "No value")
df.na.fill(fillColValues)