# 腾讯云 COS Python SDK 开发指南

> 基于腾讯云对象存储（Cloud Object Storage, COS）Python SDK 官方文档整理。

---

## 官方文档链接

| 章节 | 官方文档 |
| --- | --- |
| 快速入门 | https://cloud.tencent.com/document/product/436/12269 |
| Python SDK 常见问题 | https://cloud.tencent.com/document/product/436/56531 |
| 存储桶操作 | https://cloud.tencent.com/document/product/436/35150 |
| 上传对象 | https://cloud.tencent.com/document/product/436/65820 |
| 复制和移动对象 | https://cloud.tencent.com/document/product/436/65826 |
| 列出对象 | https://cloud.tencent.com/document/product/436/65823 |
| 判断对象是否存在 | https://cloud.tencent.com/document/product/436/65830 |
| 查询对象元数据 | https://cloud.tencent.com/document/product/436/65828 |
| 修改对象元数据 | https://cloud.tencent.com/document/product/436/65822 |
| 对象访问 URL | https://cloud.tencent.com/document/product/436/56882 |
| 生成预签名 URL | https://cloud.tencent.com/document/product/436/35153 |
| 恢复归档对象 | https://cloud.tencent.com/document/product/436/65827 |
| 检索对象内容 | https://cloud.tencent.com/document/product/436/65829 |
| 对象加密 | https://cloud.tencent.com/document/product/436/63744 |
| 存储桶加密 | https://cloud.tencent.com/document/product/436/63745 |
| 客户端加密 | https://cloud.tencent.com/document/product/436/65834 |
| 单链接限速 | https://cloud.tencent.com/document/product/436/65825 |
| 图片持久化处理 | https://cloud.tencent.com/document/product/436/55344 |
| 图片高级压缩 | https://cloud.tencent.com/document/product/436/120479 |
| 盲水印 | https://cloud.tencent.com/document/product/436/55346 |

---

## 目录

1. [环境配置与安装](#1-环境配置与安装)
2. [初始化 COS 客户端](#2-初始化-cos-客户端)
3. [存储桶操作](#3-存储桶操作)
4. [上传对象](#4-上传对象)
5. [下载对象](#5-下载对象)
6. [复制与移动对象](#6-复制与移动对象)
7. [列出对象](#7-列出对象)
8. [判断对象是否存在](#8-判断对象是否存在)
9. [查询对象元数据](#9-查询对象元数据)
10. [修改对象元数据](#10-修改对象元数据)
11. [对象访问 URL](#11-对象访问-url)
12. [生成预签名 URL](#12-生成预签名-url)
13. [恢复归档对象](#13-恢复归档对象)
14. [检索对象内容](#14-检索对象内容)
15. [服务端加密](#15-服务端加密)
16. [客户端加密](#16-客户端加密)
17. [单链接限速](#17-单链接限速)
18. [图片持久化处理](#18-图片持久化处理)
19. [图片高级压缩](#19-图片高级压缩)
20. [盲水印](#20-盲水印)
21. [常见问题](#21-常见问题)

---

## 1. 环境配置与安装

> 官方文档：https://cloud.tencent.com/document/product/436/12269

### 环境要求

- Python 2.7 及 Python 3.4 及以上

### 安装 SDK

```bash
# 推荐: pip 安装
pip install -U cos-python-sdk-v5

# 手动安装 (从源码)
python setup.py install

# 离线安装
mkdir cos-python-sdk-packages
pip download cos-python-sdk-v5 -d cos-python-sdk-packages
tar -czvf cos-python-sdk-packages.tar.gz cos-python-sdk-packages
# 拷贝到目标机器后:
tar -xzvf cos-python-sdk-packages.tar.gz
pip install cos-python-sdk-v5 --no-index -f cos-python-sdk-packages
```

---

## 2. 初始化 COS 客户端

### 基本初始化（默认域名）

```python
from qcloud_cos import CosConfig
from qcloud_cos import CosS3Client
import os

secret_id = os.environ['COS_SECRET_ID']
secret_key = os.environ['COS_SECRET_KEY']
region = 'ap-beijing'  # 替换为实际 region
token = None           # 永久密钥不填, 临时密钥需填入
scheme = 'https'

config = CosConfig(
    Region=region,
    SecretId=secret_id,
    SecretKey=secret_key,
    Token=token,
    Scheme=scheme
)
client = CosS3Client(config)
```

> **注意：** 一个 region 只需生成一个 `CosS3Client` 实例并复用，不要每次请求都创建新实例。

### 临时密钥初始化

```python
config = CosConfig(
    Region=region,
    SecretId=tmp_secret_id,
    SecretKey=tmp_secret_key,
    Token=token,
    Scheme=scheme
)
client = CosS3Client(config)
```

### 全球加速域名初始化

```python
config = CosConfig(
    Region=None,
    SecretId=secret_id,
    SecretKey=secret_key,
    Token=token,
    Endpoint='cos.accelerate.myqcloud.com',
    Scheme=scheme
)
client = CosS3Client(config)
```

### 自定义域名初始化

```python
config = CosConfig(
    Region=None,
    SecretId=secret_id,
    SecretKey=secret_key,
    Token=token,
    Domain='user-define.example.com',
    Scheme=scheme
)
client = CosS3Client(config)
```

### 代理初始化

```python
proxies = {
    'http': '127.0.0.1:80',
    'https': '127.0.0.1:443'
}
config = CosConfig(
    Region=region,
    SecretId=secret_id,
    SecretKey=secret_key,
    Token=token,
    Proxies=proxies
)
client = CosS3Client(config)
```

---

## 3. 存储桶操作

> 官方文档：https://cloud.tencent.com/document/product/436/35150

### 查询存储桶列表

```python
response = client.list_buckets()
for bucket in response['Buckets']['Bucket']:
    print(bucket['Name'], bucket['Location'], bucket['CreationDate'])
```

### 创建存储桶

```python
response = client.create_bucket(
    Bucket='examplebucket-1250000000',
    ACL='private'  # 可选: 'private', 'public-read', 'public-read-write'
)
```

### 检索存储桶

```python
response = client.head_bucket(Bucket='examplebucket-1250000000')
print(response)
```

### 删除存储桶

```python
client.delete_bucket(Bucket='examplebucket-1250000000')
```

### 判断存储桶是否存在

```python
exists = client.bucket_exists(Bucket='examplebucket-1250000000')
print(exists)  # True / False
```

---

## 4. 上传对象

> 官方文档：https://cloud.tencent.com/document/product/436/65820

### 高级接口（推荐，支持断点续传）

根据文件大小自动选择简单上传或分块上传，分块上传支持断点续传。

```python
response = client.upload_file(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    LocalFilePath='local.txt',
    PartSize=1,        # 分块大小，单位 MB，默认 1
    MAXThread=5,       # 并发线程数，默认 5
    EnableMD5=False
)
print(response['ETag'])
```

#### 带进度回调

```python
import sys

def upload_percentage(consumed_bytes, total_bytes):
    if total_bytes:
        rate = int(100 * (float(consumed_bytes) / float(total_bytes)))
        print('\r{0}% '.format(rate))
        sys.stdout.flush()

response = client.upload_file(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    LocalFilePath='local.txt',
    PartSize=1,
    MAXThread=5,
    progress_callback=upload_percentage,
    StorageClass='STANDARD',
    Metadata={'x-cos-meta-key1': 'value1'}
)
```

#### 断点续传（失败重试）

```python
from qcloud_cos.cos_exception import CosClientError, CosServiceError

for i in range(10):
    try:
        response = client.upload_file(
            Bucket='examplebucket-1250000000',
            Key='exampleobject',
            LocalFilePath='local.txt'
        )
        break
    except (CosClientError, CosServiceError) as e:
        print(e)
```

### 简单上传（不超过 5GB）

```python
# 文件流上传
with open('test.txt', 'rb') as fp:
    response = client.put_object(
        Bucket='examplebucket-1250000000',
        Body=fp,
        Key='test.txt',
        StorageClass='STANDARD',
        ContentType='text/html; charset=utf-8'
    )
print(response['ETag'])

# 字节流上传
response = client.put_object(
    Bucket='examplebucket-1250000000',
    Body=b'abcdefg',
    Key='test.txt'
)

# 本地路径上传
response = client.put_object_from_local_file(
    Bucket='examplebucket-1250000000',
    LocalFilePath='local.txt',
    Key='test.txt'
)
```

### 创建目录

```python
response = client.put_object(
    Bucket='examplebucket-1250000000',
    Key='path/to/create/dir/',
    Body=b''
)
```

### 批量上传（文件夹上传）

```python
from qcloud_cos.cos_threadpool import SimpleThreadPool

uploadDir = '/root/logs'
bucket = 'examplebucket-1250000000'
pool = SimpleThreadPool()

for path, dir_list, file_list in os.walk(uploadDir):
    for file_name in file_list:
        localFilePath = os.path.join(path, file_name)
        cosObjectKey = localFilePath.strip('/')
        pool.add_task(client.upload_file, bucket, cosObjectKey, localFilePath)

pool.wait_completion()
result = pool.get_result()
if not result['success_all']:
    print("Not all files upload successed. you should retry")
```

### 分块上传（手动控制）

```python
# 1. 初始化分块上传
response = client.create_multipart_upload(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    StorageClass='STANDARD'
)
uploadId = response['UploadId']

# 2. 上传分块（最多 10000 块）
response = client.upload_part(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    Body=b'b' * 1024 * 1024,
    PartNumber=1,
    UploadId=uploadId
)
etag = response['ETag']

# 3. 查询已上传分块
response = client.list_parts(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    UploadId=uploadId
)

# 4. 完成分块上传
response = client.complete_multipart_upload(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    UploadId=uploadId,
    MultipartUpload={
        'Part': [
            {'ETag': 'string', 'PartNumber': 1},
            {'ETag': 'string', 'PartNumber': 2},
        ]
    }
)

# 终止分块上传
client.abort_multipart_upload(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    UploadId=uploadId
)
```

---

## 5. 下载对象

> 官方文档：https://cloud.tencent.com/document/product/436/65820

```python
# 下载到本地文件
response = client.get_object(
    Bucket='examplebucket-1250000000',
    Key='exampleobject'
)
response['Body'].get_stream_to_file('output.txt')

# 获取文件流
response = client.get_object(
    Bucket='examplebucket-1250000000',
    Key='exampleobject'
)
fp = response['Body'].get_raw_stream()
print(fp.read(2))

# 指定下载范围
response = client.get_object(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    Range='bytes=0-10'
)

# 设置响应头部
response = client.get_object(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    ResponseContentType='text/html; charset=utf-8'
)
```

---

## 6. 复制与移动对象

> 官方文档：https://cloud.tencent.com/document/product/436/65826

### 高级复制接口（推荐）

小于 5GB 调用 `copy_object`，大于等于 5GB 调用分块复制。

```python
response = client.copy(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    CopySource={
        'Bucket': 'sourcebucket-1250000000',
        'Key': 'sourceobject',
        'Region': 'ap-guangzhou'
    }
)
```

### 移动对象（复制 + 删除）

```python
bucket = 'examplebucket-1250000000'
srcKey = 'src_object_key'
destKey = 'dest_object_key'

response = client.copy(
    Bucket=bucket,
    Key=destKey,
    CopySource={
        'Bucket': bucket,
        'Key': srcKey,
        'Region': 'ap-guangzhou'
    }
)
client.delete_object(Bucket=bucket, Key=srcKey)
```

### 简单复制（不超过 5GB）

```python
response = client.copy_object(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    CopySource={
        'Bucket': 'sourcebucket-1250000000',
        'Key': 'sourceobject',
        'Region': 'ap-guangzhou'
    }
)
```

---

## 7. 列出对象

> 官方文档：https://cloud.tencent.com/document/product/436/65823

### 列出第一页对象

```python
response = client.list_objects(Bucket='examplebucket-1250000000')
if 'Contents' in response:
    for content in response['Contents']:
        print(content['Key'])
```

### 按前缀列出

```python
response = client.list_objects(
    Bucket='examplebucket-1250000000',
    Prefix='folder1/'
)
```

### 分页列出全部对象

```python
marker = ""
while True:
    response = client.list_objects(
        Bucket='examplebucket-1250000000',
        Prefix='folder1/',
        Marker=marker,
        MaxKeys=10
    )
    if 'Contents' in response:
        for content in response['Contents']:
            print(content['Key'])
    if response['IsTruncated'] == 'false':
        break
    marker = response["NextMarker"]
```

### 列出目录下的对象和子目录

```python
response = client.list_objects(
    Bucket='examplebucket-1250000000',
    Prefix='folder1/',
    Delimiter='/'
)
# 文件列表
if 'Contents' in response:
    for content in response['Contents']:
        print(content['Key'])
# 子目录
if 'CommonPrefixes' in response:
    for folder in response['CommonPrefixes']:
        print(folder['Prefix'])
```

### 列出对象历史版本

```python
response = client.list_objects_versions(
    Bucket='examplebucket-1250000000',
    Prefix='string'
)
```

---

## 8. 判断对象是否存在

> 官方文档：https://cloud.tencent.com/document/product/436/65830

```python
exists = client.object_exists(
    Bucket='examplebucket-1250000000',
    Key='exampleobject'
)
print(exists)  # True / False
```

---

## 9. 查询对象元数据

> 官方文档：https://cloud.tencent.com/document/product/436/65828

```python
response = client.head_object(
    Bucket='examplebucket-1250000000',
    Key='exampleobject'
)
print(response['Content-Length'])
print(response['ETag'])
print(response['Last-Modified'])
print(response.get('x-cos-meta-test'))
```

---

## 10. 修改对象元数据

> 官方文档：https://cloud.tencent.com/document/product/436/65822

通过 `copy_object` 并设置 `CopyStatus='Replaced'` 实现，源和目标是同一个对象：

```python
response = client.copy_object(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    CopySource={
        'Bucket': 'examplebucket-1250000000',
        'Key': 'exampleobject',
        'Region': 'ap-guangzhou'
    },
    CopyStatus='Replaced',
    ContentType='text/plain',
    Metadata={'x-cos-meta-key1': 'value1', 'x-cos-meta-key2': 'value2'}
)
```

### 修改存储类型

```python
response = client.copy_object(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    CopySource={
        'Bucket': 'examplebucket-1250000000',
        'Key': 'exampleobject',
        'Region': 'ap-guangzhou'
    },
    CopyStatus='Replaced',
    StorageClass='STANDARD_IA'
)
```

---

## 11. 对象访问 URL

> 官方文档：https://cloud.tencent.com/document/product/436/56882

生成匿名下载或分发的对象访问 URL（**公有读**对象可直接访问，**私有读**需要预签名 URL）。

```python
url = client.get_object_url(
    Bucket='examplebucket-1250000000',
    Key='exampleobject'
)
print(url)
```

---

## 12. 生成预签名 URL

> 官方文档：https://cloud.tencent.com/document/product/436/35153

### 上传预签名 URL

```python
url = client.get_presigned_url(
    Method='PUT',
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    Expired=120  # 秒
)
print(url)

# 使用 URL 上传
import requests
response = requests.put(url=url, data=b'123')
```

#### 限制存储类型和上传速度

```python
url = client.get_presigned_url(
    Method='PUT',
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    Headers={
        'x-cos-storage-class': 'STANDARD_IA',
        'x-cos-traffic-limit': '819200'
    },
    Expired=300
)
```

### 下载预签名 URL

```python
url = client.get_presigned_url(
    Method='GET',
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    Expired=120
)

# 指定下载文件名
url = client.get_presigned_url(
    Method='GET',
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    Params={
        'response-content-disposition': 'attachment; filename=example.xlsx'
    },
    Expired=120
)
```

### 便捷下载预签名接口

```python
url = client.get_presigned_download_url(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    Expired=120
)
```

### 临时密钥预签名

```python
url = client.get_presigned_url(
    Method='GET',
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    Params={'x-cos-security-token': 'string'},
    Expired=120,
    SignHost=False
)
```

### 域名不签入签名

当分发后使用者需修改请求域名时：

```python
url = client.get_presigned_url(
    Method='GET',
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    SignHost=False,
    Expired=120
)
```

---

## 13. 恢复归档对象

> 官方文档：https://cloud.tencent.com/document/product/436/65827

```python
response = client.restore_object(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    RestoreRequest={
        'Days': 100,
        'CASJobParameters': {
            'Tier': 'Standard'  # 归档: Expedited/Standard/Bulk; 深度归档: Standard/Bulk
        }
    }
)
```

---

## 14. 检索对象内容

> 官方文档：https://cloud.tencent.com/document/product/436/65829

使用 SQL 从 CSV/JSON 对象中检索内容（对象需 UTF-8 编码）。

```python
response = client.select_object_content(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    Expression='Select * from COSObject',
    ExpressionType='SQL',
    InputSerialization={
        'CompressionType': 'NONE',
        'JSON': {'Type': 'LINES'}
    },
    OutputSerialization={
        'CSV': {'RecordDelimiter': '\n'}
    }
)
event_stream = response['Payload']
result = event_stream.get_select_result()
print(result)
```

---

## 15. 服务端加密

> 官方文档（对象加密）：https://cloud.tencent.com/document/product/436/63744  
> 官方文档（存储桶加密）：https://cloud.tencent.com/document/product/436/63745

### SSE-COS 加密（COS 托管密钥）

```python
# 上传
response = client.put_object(
    Bucket='examplebucket-1250000000',
    Key='sdk-sse-cos',
    Body='123',
    ServerSideEncryption='AES256'
)

# 下载（自动解密，无需额外参数）
response = client.get_object(
    Bucket='examplebucket-1250000000',
    Key='sdk-sse-cos'
)
```

### SSE-KMS 加密（KMS 托管密钥，必须 HTTPS）

```python
import base64
from qcloud_cos.cos_comm import to_bytes

response = client.put_object(
    Bucket='examplebucket-1250000000',
    Key='sdk-sse-kms',
    Body='123',
    ServerSideEncryption='cos/kms',
    SSEKMSKeyId='kms-key-id',  # 可选，不填则用 COS 默认 CMK
    SSEKMSContext=base64.standard_b64encode(to_bytes('{"test":"test"}'))
)
```

### SSE-C 加密（用户提供密钥，必须 HTTPS）

```python
import base64
from qcloud_cos.cos_comm import get_md5, to_bytes

ssec_secret = '00000000000000000000000000000001'  # 32 字节
ssec_key = base64.standard_b64encode(to_bytes(ssec_secret))
ssec_key_md5 = get_md5(ssec_secret)

# 上传
response = client.put_object(
    Bucket='examplebucket-1250000000',
    Key='sdk-sse-c',
    Body='00000',
    SSECustomerAlgorithm='AES256',
    SSECustomerKey=ssec_key,
    SSECustomerKeyMD5=ssec_key_md5
)

# 下载（必须携带相同密钥）
response = client.get_object(
    Bucket='examplebucket-1250000000',
    Key='sdk-sse-c',
    SSECustomerAlgorithm='AES256',
    SSECustomerKey=ssec_key,
    SSECustomerKeyMD5=ssec_key_md5
)
```

### 存储桶加密

```python
# 设置
client.put_bucket_encryption(
    Bucket='examplebucket-1250000000',
    ServerSideEncryptionConfiguration={
        'Rule': [{'ApplySideEncryptionConfiguration': {'SSEAlgorithm': 'AES256'}}]
    }
)

# 查询
response = client.get_bucket_encryption(Bucket='examplebucket-1250000000')

# 删除
client.delete_bucket_encryption(Bucket='examplebucket-1250000000')
```

---

## 16. 客户端加密

> 官方文档：https://cloud.tencent.com/document/product/436/65834

### 对称 AES256 加密

```python
from qcloud_cos.cos_encryption_client import CosEncryptionClient
from qcloud_cos.crypto import AESProvider

# 通过密钥值初始化（aes_key_value 需 base64 编码后的 32 字节密钥）
aes_provider = AESProvider(aes_key='aes_key_value')
# 或通过密钥文件路径
# aes_provider = AESProvider(aes_key_path='aes_key_path')

client_for_aes = CosEncryptionClient(config, aes_provider)

# 上传
client_for_aes.put_object(
    Bucket='examplebucket-1250000000',
    Body=b'bytes',
    Key='exampleobject'
)

# 下载
response = client_for_aes.get_object(
    Bucket='examplebucket-1250000000',
    Key='exampleobject'
)

# 断点续传上传（partsize 必须为 16 字节整数倍）
client_for_aes.upload_file(
    Bucket='examplebucket-1250000000',
    LocalFilePath='local.txt',
    Key='exampleobject',
    PartSize=10,
    MAXThread=10
)
```

### 非对称 RSA 加密

```python
from qcloud_cos.cos_encryption_client import CosEncryptionClient
from qcloud_cos.crypto import RSAProvider

rsa_key_pair = RSAProvider.get_rsa_key_pair('public_key_value', 'private_key_value')
# 或通过路径
# rsa_key_pair = RSAProvider.get_rsa_key_pair_path('public_key_path', 'private_key_path')

rsa_provider = RSAProvider(key_pair_info=rsa_key_pair)
client_for_rsa = CosEncryptionClient(config, rsa_provider)

# 上传 / 下载 / 分块上传 接口与 AES 加密客户端一致
```

---

## 17. 单链接限速

> 官方文档：https://cloud.tencent.com/document/product/436/65825

限速值范围：**819200 - 838860800**（bit/s），即 800Kb/s - 800Mb/s。

```python
# 上传限速
with open('test.bin', 'rb') as fp:
    response = client.put_object(
        Bucket='examplebucket-1250000000',
        Key='exampleobject',
        Body=fp,
        TrafficLimit='819200'
    )

# 下载限速
response = client.get_object(
    Bucket='examplebucket-1250000000',
    Key='exampleobject',
    TrafficLimit='819200'
)
response['Body'].get_stream_to_file('exampleobject')
```

---

## 18. 图片持久化处理

> 官方文档：https://cloud.tencent.com/document/product/436/55344

### 上传时处理

```python
import json

response, data = client.ci_put_object(
    Bucket='examplebucket-1250000000',
    Body=open('local.jpg', 'rb'),
    Key='local.jpg',
    PicOperations=json.dumps({
        "is_pic_info": 1,
        "rules": [{
            "fileid": "format.png",
            "rule": "imageView2/format/png"
        }]
    })
)
```

### 云上数据处理

```python
response, data = client.ci_image_process(
    Bucket='examplebucket-1250000000',
    Key='local.jpg',
    PicOperations=json.dumps({
        "is_pic_info": 1,
        "rules": [{
            "fileid": "format.png",
            "rule": "imageView2/format/png"
        }]
    })
)
```

**PicOperations rules 参数说明：**

| 参数   | 描述                                                       | 必选 |
| ------ | ---------------------------------------------------------- | ---- |
| bucket | 目标存储桶名称，不指定则保存到当前桶                   | 否   |
| fileid | 结果文件路径，以 `/` 开头存入指定文件夹，否则存入同目录 | 是   |
| rule   | 处理参数，参见数据万象图片处理 API                   | 是   |

---

## 19. 图片高级压缩

> 官方文档：https://cloud.tencent.com/document/product/436/120479
>
> 需先在控制台开通图片高级压缩服务。

```python
# TPG 压缩
client.ci_download_compress_image(
    Bucket='examplebucket-1250000000',
    Key='sample.png',
    DestImagePath='sample.tpg',
    CompressType='tpg'
)

# HEIF 压缩
client.ci_download_compress_image(
    Bucket='examplebucket-1250000000',
    Key='sample.png',
    DestImagePath='sample.heif',
    CompressType='heif'
)

# AVIF 压缩
client.ci_download_compress_image(
    Bucket='examplebucket-1250000000',
    Key='sample.png',
    DestImagePath='sample.avif',
    CompressType='avif'
)
```

支持格式：`tpg`、`heif`、`avif`、`svg`

---

## 20. 盲水印

> 官方文档：https://cloud.tencent.com/document/product/436/55346

```python
import base64

# 添加盲水印
watermark_url = 'http://examplebucket-1250000000.cos.ap-beijing.myqcloud.com/watermark.png'
watermark_url_base64 = base64.b64encode(watermark_url.encode()).decode()

response, data = client.ci_put_object_from_local_file(
    Bucket='examplebucket-1250000000',
    LocalFilePath='sample.png',
    Key='sample.png',
    PicOperations='{"is_pic_info":1,"rules":[{"fileid":"format.png","rule":"watermark/3/type/1/image/' + watermark_url_base64 + '"}]}'
)

# 提取盲水印
sample_url = 'http://examplebucket-1250000000.cos.ap-beijing.myqcloud.com/sample.png'
sample_url_base64 = base64.b64encode(sample_url.encode()).decode()

response, data = client.ci_put_object_from_local_file(
    Bucket='examplebucket-1250000000',
    LocalFilePath='format.png',
    Key='format.png',
    PicOperations='{"is_pic_info":1,"rules":[{"fileid":"watermark.png","rule":"watermark/4/type/1/image/' + sample_url_base64 + '"}]}'
)
```

---

## 21. 常见问题

> 官方文档：https://cloud.tencent.com/document/product/436/56531

### Q: 升级后无法执行"移动文件"操作？

COS V5 不支持移动文件接口。使用 `copy_object` + `delete_object` 实现。建议删除前校验数据 MD5 一致性。

### Q: 如何获取下载文件的临时链接？

使用 `get_presigned_url` 或 `get_presigned_download_url`。使用临时密钥时需在 header 或 query_string 中加上 `x-cos-security-token`。

### Q: 出现异常如何处理？

操作成功返回 `dict` 或 `None`。失败抛出：
- `CosClientError`：客户端异常（网络、文件 IO、参数校验等）
- `CosServiceError`：服务端异常（文件不存在、无权限等）

### Q: 上传时报 `Request has expired`？

签名过期，重新生成签名。若仍报错，检查机器本地时间是否为标准北京时间。

---

## 附录：存储类型

| 值            | 说明       |
| ------------- | ---------- |
| STANDARD      | 标准存储   |
| STANDARD_IA   | 低频存储   |
| ARCHIVE       | 归档存储   |

## 附录：Region 列表

完整列表参见：https://cloud.tencent.com/document/product/436/6224

常用 Region：

| Region         | 地域       |
| -------------- | ---------- |
| ap-beijing     | 北京       |
| ap-shanghai    | 上海       |
| ap-guangzhou   | 广州       |
| ap-chengdu     | 成都       |
| ap-hongkong    | 中国香港   |
| ap-singapore   | 新加坡     |
| na-siliconvalley | 硅谷     |
| eu-frankfurt   | 法兰克福   |