如何编写上传大于RAM的文件的Python代码？

import os
from qcloud_cos import CosConfig
from qcloud_cos import CosS3Client

# 配置腾讯云COS的密钥信息
secret_id = 'your_secret_id'
secret_key = 'your_secret_key'
region = 'your_region'
bucket = 'your_bucket'

# 初始化COS客户端
config = CosConfig(Region=region, SecretId=secret_id, SecretKey=secret_key)
client = CosS3Client(config)

# 分片上传大文件
def upload_large_file(file_path, key):
    # 获取文件大小
    file_size = os.path.getsize(file_path)
    
    # 设置分片大小（这里设置为5MB）
    chunk_size = 5 * 1024 * 1024
    
    # 初始化分片上传
    response = client.create_multipart_upload(
        Bucket=bucket,
        Key=key
    )
    upload_id = response['UploadId']
    
    # 分片上传
    parts = []
    offset = 0
    part_number = 1
    while offset < file_size:
        # 读取分片数据
        data = open(file_path, 'rb').read(chunk_size)
        
        # 上传分片
        response = client.upload_part(
            Bucket=bucket,
            Key=key,
            Body=data,
            PartNumber=part_number,
            UploadId=upload_id
        )
        etag = response['ETag']
        
        # 记录分片信息
        parts.append({
            'PartNumber': part_number,
            'ETag': etag
        })
        
        # 更新偏移量和分片序号
        offset += chunk_size
        part_number += 1
    
    # 完成分片上传
    response = client.complete_multipart_upload(
        Bucket=bucket,
        Key=key,
        UploadId=upload_id,
        MultipartUpload={'Parts': parts}
    )
    
    # 打印上传结果
    print(response)

# 调用函数上传文件
upload_large_file('path/to/large_file', 'key/to/upload')