In short, I'm leveraging spark-xml to do some parsing of XML files. However, using this is removing the leading zeros in all the values I'm interested in. However, I need the final output, which is a DataFrame, to include the leading zeros. I'm unsure/can not figure out a way to add leading zeros to the columns I'm interested in.
val df = spark.read
.format("com.databricks.spark.xml")
.option("rowTag", "output")
.option("excludeAttribute", true)
.option("allowNumericLeadingZeros", true) //including this does not solve the problem
.load("pathToXmlFile")
Example output that I'm getting
+------+---+--------------------+
|iD |val|Code |
+------+---+--------------------+
|1 |44 |9022070536692784476 |
|2 |66 |-5138930048185086175|
|3 |25 |805582856291361761 |
|4 |17 |-9107885086776983000|
|5 |18 |1993794295881733178 |
|6 |31 |-2867434050463300064|
|7 |88 |-4692317993930338046|
|8 |44 |-4039776869915039812|
|9 |20 |-5786627276152563542|
|10 |12 |7614363703260494022 |
+------+---+--------------------+
Desired output
+--------+----+--------------------+
|iD |val |Code |
+--------+----+--------------------+
|001 |044 |9022070536692784476 |
|002 |066 |-5138930048185086175|
|003 |025 |805582856291361761 |
|004 |017 |-9107885086776983000|
|005 |018 |1993794295881733178 |
|006 |031 |-2867434050463300064|
|007 |088 |-4692317993930338046|
|008 |044 |-4039776869915039812|
|009 |020 |-5786627276152563542|
|0010 |012 |7614363703260494022 |
+--------+----+--------------------+
You can simply do that by using concat inbuilt function
df.withColumn("iD", concat(lit("00"), col("iD")))
.withColumn("val", concat(lit("0"), col("val")))
This solved it for me, thank you all for the help
val df2 = df
.withColumn("idLong", format_string("%03d", $"iD"))
来源：https://stackoverflow.com/questions/50047444/add-leading-zeros-to-columns-in-a-spark-data-frame