如何拆分spark dataframe列字符串？

from pyspark.sql import SparkSession
from pyspark.sql.functions import split

# 创建SparkSession
spark = SparkSession.builder.getOrCreate()

# 创建示例DataFrame
data = [("John,Doe", 25), ("Jane,Smith", 30), ("Tom,Hanks", 40)]
df = spark.createDataFrame(data, ["name", "age"])

# 使用split函数拆分name列的字符串
df = df.withColumn("first_name", split(df.name, ",").getItem(0))
df = df.withColumn("last_name", split(df.name, ",").getItem(1))

# 显示结果
df.show()

+----------+---+----------+---------+
|      name|age|first_name|last_name|
+----------+---+----------+---------+
|  John,Doe| 25|      John|      Doe|
|Jane,Smith| 30|      Jane|    Smith|
| Tom,Hanks| 40|       Tom|    Hanks|
+----------+---+----------+---------+