Azure Storage Blob Py

作者 microsoft354361d83247MIT收录于 2026年10月8日更新于 2026年10月8日

Azure Blob Storage SDK for Python. Use for uploading, downloading, listing blobs, managing containers, and blob lifecycle. Triggers: "blob storage", "BlobServiceClient", "ContainerClient", "BlobClient", "upload blob", "download blob".

精选仅含说明Software Development
AI 生成的概览

指导 Python 开发者使用 Azure Blob Storage SDK 进行上传、下载、列出和容器管理。

功能
该技能为 Python 版 Azure Blob Storage SDK 提供参考说明和代码示例。内容涵盖使用 DefaultAzureCredential 进行身份验证、客户端层次结构、容器和 Blob 操作、性能调优、SAS 令牌生成、元数据处理以及异步模式。它产出的是指导和示例代码,而非可执行脚本。
适用场景
在编写与 Azure Blob Storage 交互的 Python 代码时使用此技能,例如上传或下载 Blob、列出容器或管理 Blob 生命周期。当需要关于身份验证、性能调优或异步客户端用法的指导时也适用。
运行要求
需要安装 azure-storage-blob 和 azure-identity 包的 Python 环境。实际执行操作需要访问 Azure 存储账户并具备相应凭据。该技能仅包含说明,不附带可执行脚本。

Azure Blob Storage SDK for Python

Client library for Azure Blob Storage — object storage for unstructured data.

Installation

bash
pip install azure-storage-blob azure-identity

Environment Variables

bash
AZURE_STORAGE_ACCOUNT_NAME=<your-storage-account>  # Required for all auth methods# Or use full URLAZURE_STORAGE_ACCOUNT_URL=https://<account>.blob.core.windows.net  # Alternative to account nameAZURE_TOKEN_CREDENTIALS=prod # Required only if DefaultAzureCredential is used in production

Authentication & Lifecycle

🔑 Two rules apply to every code sample below:

  1. Prefer DefaultAzureCredential. It works locally (Azure CLI / VS Code / Developer CLI) and in Azure (managed identity, workload identity) with no code change. Avoid connection strings, account/API keys — they bypass Entra audit and rotation.
    • Local dev: DefaultAzureCredential works as-is.
    • Production: set AZURE_TOKEN_CREDENTIALS=prod (or AZURE_TOKEN_CREDENTIALS=<specific_credential>) to constrain the credential chain to production-safe credentials.
  2. Wrap every client in a context manager so HTTP transports, sockets, and token caches are released deterministically:
    • Sync: with <Client>(...) as client:
    • Async: async with <Client>(...) as client: and async with DefaultAzureCredential() as credential: (from azure.identity.aio)

Snippets may abbreviate this setup, but production code should always follow both rules.

python
from azure.identity import DefaultAzureCredential, ManagedIdentityCredentialfrom azure.storage.blob import BlobServiceClient
# Local dev: DefaultAzureCredential. Production: set AZURE_TOKEN_CREDENTIALS=prod or AZURE_TOKEN_CREDENTIALS=<specific_credential>credential = DefaultAzureCredential(require_envvar=True)# Or use a specific credential directly in production:# See https://learn.microsoft.com/python/api/overview/azure/identity-readme?view=azure-python#credential-classes# credential = ManagedIdentityCredential()account_url = "https://<account>.blob.core.windows.net"
with BlobServiceClient(account_url, credential=credential) as blob_service_client:    # Use blob_service_client here (see following sections for operations)    ...

Client Hierarchy

ClientPurposeGet From
BlobServiceClientAccount-level operationsDirect instantiation
ContainerClientContainer operationsblob_service_client.get_container_client()
BlobClientSingle blob operationscontainer_client.get_blob_client()

Core Workflow

Create Container

python
container_client = blob_service_client.get_container_client("mycontainer")container_client.create_container()

Upload Blob

python
# From file pathblob_client = blob_service_client.get_blob_client(    container="mycontainer",    blob="sample.txt")
with open("./local-file.txt", "rb") as data:    blob_client.upload_blob(data, overwrite=True)
# From bytes/stringblob_client.upload_blob(b"Hello, World!", overwrite=True)
# From streamimport iostream = io.BytesIO(b"Stream content")blob_client.upload_blob(stream, overwrite=True)

Download Blob

python
blob_client = blob_service_client.get_blob_client(    container="mycontainer",    blob="sample.txt")
# To filewith open("./downloaded.txt", "wb") as file:    download_stream = blob_client.download_blob()    file.write(download_stream.readall())
# To memorydownload_stream = blob_client.download_blob()content = download_stream.readall()  # bytes
# Read into existing bufferstream = io.BytesIO()num_bytes = blob_client.download_blob().readinto(stream)

List Blobs

python
container_client = blob_service_client.get_container_client("mycontainer")
# List all blobsfor blob in container_client.list_blobs():    print(f"{blob.name} - {blob.size} bytes")
# List with prefix (folder-like)for blob in container_client.list_blobs(name_starts_with="logs/"):    print(blob.name)
# Walk blob hierarchy (virtual directories)for item in container_client.walk_blobs(delimiter="/"):    if item.get("prefix"):        print(f"Directory: {item['prefix']}")    else:        print(f"Blob: {item.name}")

Delete Blob

python
blob_client.delete_blob()
# Delete with snapshotsblob_client.delete_blob(delete_snapshots="include")

Performance Tuning

python
# Configure chunk sizes for large uploads/downloadswith BlobClient(    account_url=account_url,    container_name="mycontainer",    blob_name="large-file.zip",    credential=credential,    max_block_size=4 * 1024 * 1024,  # 4 MiB blocks    max_single_put_size=64 * 1024 * 1024  # 64 MiB single upload limit) as blob_client:    # Parallel upload    blob_client.upload_blob(data, max_concurrency=4)
    # Parallel download    download_stream = blob_client.download_blob(max_concurrency=4)

SAS Tokens (User Delegation)

Generate SAS tokens with a user delegation key signed by Microsoft Entra ID — never with an account key. This keeps SAS issuance tied to Entra audit/rotation.

python
from datetime import datetime, timedelta, timezonefrom azure.identity import DefaultAzureCredentialfrom azure.storage.blob import (    BlobServiceClient,    BlobSasPermissions,    generate_blob_sas,)
now = datetime.now(timezone.utc)account_url = "https://<account>.blob.core.windows.net"
with BlobServiceClient(account_url, credential=DefaultAzureCredential()) as service:    # Get a user delegation key (valid up to 7 days). Caller needs the    # "Storage Blob Delegator" role on the storage account.    udk = service.get_user_delegation_key(        key_start_time=now,        key_expiry_time=now + timedelta(hours=1),    )
    sas_token = generate_blob_sas(        account_name="<account>",        container_name="mycontainer",        blob_name="sample.txt",        user_delegation_key=udk,        permission=BlobSasPermissions(read=True),        expiry=now + timedelta(hours=1),    )
blob_url = f"{account_url}/mycontainer/sample.txt?{sas_token}"

Blob Properties and Metadata

python
# Get propertiesproperties = blob_client.get_blob_properties()print(f"Size: {properties.size}")print(f"Content-Type: {properties.content_settings.content_type}")print(f"Last modified: {properties.last_modified}")
# Set metadatablob_client.set_blob_metadata(metadata={"category": "logs", "year": "2024"})
# Set content typefrom azure.storage.blob import ContentSettingsblob_client.set_http_headers(    content_settings=ContentSettings(content_type="application/json"))

Async Client

python
from azure.identity.aio import DefaultAzureCredentialfrom azure.storage.blob.aio import BlobServiceClient
async def upload_async():    async with DefaultAzureCredential() as credential:        async with BlobServiceClient(account_url, credential=credential) as client:            blob_client = client.get_blob_client("mycontainer", "sample.txt")                        with open("./file.txt", "rb") as data:                await blob_client.upload_blob(data, overwrite=True)
# Download asyncasync def download_async():    async with BlobServiceClient(account_url, credential=credential) as client:        blob_client = client.get_blob_client("mycontainer", "sample.txt")                stream = await blob_client.download_blob()        data = await stream.readall()

Best Practices

  1. Pick sync OR async and stay consistent. Do not mix azure.storage.blob sync clients with azure.storage.blob.aio async clients in the same call path. Choose one mode per module.
  2. Always use context managers for clients and async credentials. Wrap every client in with BlobServiceClient(...) as client: (sync) or async with BlobServiceClient(...) as client: (async). For async DefaultAzureCredential from azure.identity.aio, also use async with credential: so tokens and transports are cleaned up.
  3. Use DefaultAzureCredential for code that runs locally (instead of connection strings). Use a specific token credential for code that runs in Azure.
  4. Set overwrite=True explicitly when re-uploading
  5. Use max_concurrency for large file transfers
  6. Prefer readinto() over readall() for memory efficiency
  7. Use walk_blobs() for hierarchical listing
  8. Set appropriate content types for web-served blobs

Reference Files

FileContents
references/capabilities.md [blocked]Capability index mapping hero flows and non-hero references.
references/non-hero-scenarios.md [blocked]Dedicated non-hero examples (metadata/properties and async patterns).

来源与署名

来源:microsoft/skills位于.github/plugins/azure-sdk-python/skills/azure-storage-blob-py提交354361d

许可证: MIT

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