用python将一个文件切割成多个指定大小的文件

import os


def cut(file_path, cut_size):
    """
    将大文件切割成指定大小的小文件
    :param file_path: 文件路径
    :param cut_size: 切割后的文件大小，单位为MB
    :return: 
    """
    size = os.path.getsize(file_path)
    cut_size = cut_size * 1024 * 1024
    num = size // cut_size + 1
    sum = 0
    with open(file_path, 'rb') as f1:
        for i in range(num):
            with open('{}.zip'.format(i + 1), 'wb') as f2:
                while True:
                    if sum >= cut_size:
                        sum = 0
                        break
                    ret = f1.read(1024)
                    sum += 1024
                    f2.write(ret)