如何对PySpark DataFrame中指定列的每一行应用函数

from pyspark.sql import SparkSession
from pyspark.sql.functions import udf
from pyspark.sql.types import *

spark = SparkSession.builder.getOrCreate()

def apply_function(value):
    # 在这里定义你的函数逻辑
    result = function_name(value)
    return result

udf_apply_function = udf(apply_function, returnType=StringType())

df = spark.read.csv("path/to/file.csv", header=True)  # 加载CSV文件为DataFrame
df = df.withColumn("new_column", udf_apply_function(df["column_name"]))

df.show()