将CSV文件中的列四舍五入到固定的小数位数

import csv

def round_csv_column(csv_file, column_index, decimal_places):
    with open(csv_file, 'r') as file:
        reader = csv.reader(file)
        data = list(reader)

    for row in data:
        try:
            value = float(row[column_index])
            rounded_value = round(value, decimal_places)
            row[column_index] = str(rounded_value)
        except ValueError:
            pass  # Ignore non-numeric values

    with open(csv_file, 'w', newline='') as file:
        writer = csv.writer(file)
        writer.writerows(data)

# 示例用法
csv_file = 'data.csv'
column_index = 2  # 假设需要四舍五入的列索引为2
decimal_places = 2  # 假设需要四舍五入到2位小数

round_csv_column(csv_file, column_index, decimal_places)