在PySpark中如何将两列堆叠成一列？

from pyspark.sql import SparkSession
from pyspark.sql.functions import concat

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

# 创建示例数据
data = [("John", "Doe"), ("Jane", "Smith"), ("Alice", "Brown")]
df = spark.createDataFrame(data, ["first_name", "last_name"])

# 使用concat函数将两列堆叠成一列
df = df.withColumn("full_name", concat(df.first_name, df.last_name))

# 显示结果
df.show()

+----------+---------+----------+
|first_name|last_name|full_name |
+----------+---------+----------+
|John      |Doe      |JohnDoe   |
|Jane      |Smith    |JaneSmith |
|Alice     |Brown    |AliceBrown|
+----------+---------+----------+