如何在pyspark中循环多列中的多个衰减率

from pyspark.sql import SparkSession
from pyspark.sql.functions import col

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

# 创建示例数据
data = [(1, 10, 20, 30), (2, 15, 25, 35), (3, 20, 30, 40)]
df = spark.createDataFrame(data, ["id", "col1", "col2", "col3"])

# 定义衰减率列表
decay_rates = [0.9, 0.8, 0.7]

# 循环处理每个衰减率
for i, decay_rate in enumerate(decay_rates):
    # 定义新列名
    new_col_name = "col{}_decay".format(i+1)
    
    # 计算衰减后的值
    df = df.withColumn(new_col_name, col("col{}".format(i+1)) * decay_rate)

# 显示结果
df.show()