如何只将数据集的PySpark中的第一个字母大写？(简单大写/句子大小写)

from pyspark.sql import SparkSession
from pyspark.sql.functions import initcap

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

# 创建示例数据集
data = [("john doe", 25), ("jane smith", 30), ("bob johnson", 35)]
df = spark.createDataFrame(data, ["name", "age"])

# 使用initcap函数将name列的第一个字母大写
df = df.withColumn("name", initcap(df.name))

# 显示结果
df.show()

+-----------+---+
|       name|age|
+-----------+---+
|  John Doe| 25|
|Jane Smith| 30|
|Bob Johnson| 35|
+-----------+---+