按月划分csv文件结果

import csv
from datetime import datetime

def split_csv_by_month(csv_file):
    # 读取原始CSV文件
    with open(csv_file, 'r') as file:
        reader = csv.DictReader(file)
        data = list(reader)

    # 解析CSV文件，获取日期字段的值
    for record in data:
        date_str = record['日期']
        date = datetime.strptime(date_str, '%Y-%m-%d')
        month = date.strftime('%Y-%m')

        # 创建按月份命名的CSV文件
        month_csv_file = f'{month}.csv'
        with open(month_csv_file, 'a', newline='') as file:
            writer = csv.DictWriter(file, fieldnames=reader.fieldnames)
            if file.tell() == 0:
                writer.writeheader()

            # 将数据记录写入对应的按月份命名的CSV文件中
            writer.writerow(record)

    print('按月划分CSV文件结果已生成！')

# 调用示例
split_csv_by_month('data.csv')