我需要帮助创建一个函数，循环csv文件列表，选择某些列并再次将它们保存为csv文件

import pandas as pd

def select_columns(input_file, output_file, columns):
    df = pd.read_csv(input_file)
    df_selected = df[columns]
    df_selected.to_csv(output_file, index=False)

# CSV文件列表
csv_files = ['file1.csv', 'file2.csv', 'file3.csv']

# 选择的列
selected_columns = ['column1', 'column2', 'column3']

# 循环处理CSV文件列表
for file in csv_files:
    input_file = file
    output_file = f'selected_{file}'
    select_columns(input_file, output_file, selected_columns)