Python Minio 工具类封装

        最近因为需要对大规模的文件进行存储，选了多种对象存储方案，最终选择了MinIO，为了方便python的调用，在minio第三方包的基础上进行进一步封装调用，该工具除了基础的功能外，还封装了多线程分片下载文件和上传文件的功能，切片设置不宜过大，因为会受限于机器的带宽，过大会导致带宽被占光影响机器性能。分享的代码仅供学习使用。

import os
import io
from minio import Minio
from minio.error import S3Error
from datetime import timedelta
from tqdm import tqdm
from minio.deleteobjects import DeleteObject
from concurrent.futures import as_completed, ThreadPoolExecutor


class Bucket(object):
    client = None
    policy = '{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Principal":{"AWS":["*"]},"Action":["s3:GetBucketLocation","s3:ListBucket"],"Resource":["arn:aws:s3:::%s"]},{"Effect":"Allow","Principal":{"AWS":["*"]},"Action":["s3:GetObject"],"Resource":["arn:aws:s3:::%s/*"]}]}'

    def __new__(cls, *args, **kwargs):
        if not cls.client:
            cls.client = object.__new__(cls)
        return cls.client

    def __init__(self, service, access_key, secret_key, secure=False, section_size=10, t_max=3):
        '''
        实例化参数
        :param service: 服务器地址
        :param access_key: access_key
        :param secret_key: secret_key
        :param secure: secure
        :param section_size: 切片大小mb
        :param t_max: 线程池大小
        '''
        self.service = service
        self.client = Minio(service, access_key=access_key, secret_key=secret_key, secure=secure)
        self.size = section_size * 1024 * 1024
        self.processPool = ThreadPoolExecutor(max_workers=t_max)

    def exists_bucket(self, bucket_name):
        """
        判断桶是否存在
        :param bucket_name: 桶名称
        :return:
        """
        return self.client.bucket_exists(bucket_name=bucket_name)

    def create_bucket(self, bucket_name: str, is_policy: bool=True):
        """
        创建桶 + 赋予策略
        :param bucket_name: 桶名
        :param is_policy: 策略
        :return:
        """
        if self.exists_bucket(bucket_name=bucket_name):
            return False
        else:
            self.client.make_bucket(bucket_name=bucket_name)
        if is_policy:
            policy = self.policy % (bucket_name, bucket_name