使用 Python 针对 Azure 文件进行开发

了解有关如何使用 Python 开发应用或服务的基础知识,这些应用或服务会使用 Azure 文件存储来存储文件数据。 创建一个简单的控制台应用,并了解如何使用 Python 和 Azure 文件存储执行基本操作:

  • 创建 Azure 文件共享
  • 创建目录
  • 枚举 Azure 文件共享中的文件和目录
  • 上传、下载和删除文件
  • 使用快照创建文件共享备份

注意

由于 Azure 文件可通过 SMB 进行访问,因此可编写简单的应用程序,通过标准 Python I/O 类和函数访问 Azure 文件共享。 本文将介绍如何编写使用适用于 Python 的 Azure 存储 SDK 的应用,该 SDK 使用 Azure 文件存储 REST API 与 Azure 文件存储通信。

适用于

文件共享类型 SMB NFS
标准文件共享 (GPv2)、LRS/ZRS Yes No
标准文件共享 (GPv2)、GRS/GZRS Yes No
高级文件共享 (FileStorage),LRS Yes No

下载和安装适用于 Python 的 Azure 存储 SDK

注意

如果要从适用于 Python 的 Azure 存储 SDK 版本 0.36 或更早版本升级,请在安装最新软件包之前使用 pip uninstall azure-storage 卸载旧版 SDK。

通过 PyPI 安装

要通过 Python 包索引 (PyPI) 安装,请键入:

pip install azure-storage-file-share

设置应用程序以使用 Azure 文件

将以下代码添加到 Python 源文件顶部附近,以使用本文中的代码片段。

from azure.core.exceptions import (
    ResourceExistsError,
    ResourceNotFoundError
)

from azure.storage.fileshare import (
    ShareServiceClient,
    ShareClient,
    ShareDirectoryClient,
    ShareFileClient
)

设置与 Azure 文件的连接

通过 ShareServiceClient,可以使用共享、目录和文件。 以下代码使用存储帐户连接字符串创建 ShareServiceClient 对象。

# Create a ShareServiceClient from a connection string
service_client = ShareServiceClient.from_connection_string(connection_string)

创建 Azure 文件共享

以下代码示例使用 ShareClient 对象来创建共享(如果该共享不存在)。

def create_file_share(self, connection_string, share_name):
    try:
        # Create a ShareClient from a connection string
        share_client = ShareClient.from_connection_string(
            connection_string, share_name)

        print("Creating share:", share_name)
        share_client.create_share()

    except ResourceExistsError as ex:
        print("ResourceExistsError:", ex.message)

创建目录

可以将文件置于子目录中,不必将其全部置于根目录中,以便对存储进行有效的组织。

下面的方法通过使用 ShareDirectoryClient 对象在指定文件共享的根目录中创建一个目录。

def create_directory(self, connection_string, share_name, dir_name):
    try:
        # Create a ShareDirectoryClient from a connection string
        dir_client = ShareDirectoryClient.from_connection_string(
            connection_string, share_name, dir_name)

        print("Creating directory:", share_name + "/" + dir_name)
        dir_client.create_directory()

    except ResourceExistsError as ex:
        print("ResourceExistsError:", ex.message)

上传文件

本部分会介绍如何将文件从本地存储上传到 Azure 文件存储。

下面的方法将指定文件的内容上传到指定的 Azure 文件共享中的指定目录。

def upload_local_file(self, connection_string, local_file_path, share_name, dest_file_path):
    try:
        source_file = open(local_file_path, "rb")
        data = source_file.read()

        # Create a ShareFileClient from a connection string
        file_client = ShareFileClient.from_connection_string(
            connection_string, share_name, dest_file_path)

        print("Uploading to:", share_name + "/" + dest_file_path)
        file_client.upload_file(data)

    except ResourceExistsError as ex:
        print("ResourceExistsError:", ex.message)

    except ResourceNotFoundError as ex:
        print("ResourceNotFoundError:", ex.message)

枚举 Azure 文件共享中的文件和目录

若要列出子目录中的文件和目录,请使用 list_directories_and_files 方法。 此方法返回自动分页迭代器。 以下代码将指定目录中每个文件和子目录的名称输出到控制台。

def list_files_and_dirs(self, connection_string, share_name, dir_name):
    try:
        # Create a ShareClient from a connection string
        share_client = ShareClient.from_connection_string(
            connection_string, share_name)

        for item in list(share_client.list_directories_and_files(dir_name)):
            if item["is_directory"]:
                print("Directory:", item["name"])
            else:
                print("File:", dir_name + "/" + item["name"])

    except ResourceNotFoundError as ex:
        print("ResourceNotFoundError:", ex.message)

下载文件

若要从文件中下载数据,请使用 download_file

下面的示例演示如何使用 download_file 获取指定文件的内容并将其存储在本地(“DOWNLOADED-”会预置到文件名之前)。

def download_azure_file(self, connection_string, share_name, dir_name, file_name):
    try:
        # Build the remote path
        source_file_path = dir_name + "/" + file_name

        # Add a prefix to the filename to 
        # distinguish it from the uploaded file
        dest_file_name = "DOWNLOADED-" + file_name

        # Create a ShareFileClient from a connection string
        file_client = ShareFileClient.from_connection_string(
            connection_string, share_name, source_file_path)

        print("Downloading to:", dest_file_name)

        # Open a file for writing bytes on the local system
        with open(dest_file_name, "wb") as data:
            # Download the file from Azure into a stream
            stream = file_client.download_file()
            # Write the stream to the local file
            data.write(stream.readall())

    except ResourceNotFoundError as ex:
        print("ResourceNotFoundError:", ex.message)

创建共享快照

可以创建整个文件共享的时点副本。

def create_snapshot(self, connection_string, share_name):
    try:
        # Create a ShareClient from a connection string
        share_client = ShareClient.from_connection_string(
            connection_string, share_name)

        # Create a snapshot
        snapshot = share_client.create_snapshot()
        print("Created snapshot:", snapshot["snapshot"])

        # Return the snapshot time so 
        # it can be accessed later
        return snapshot["snapshot"]

    except ResourceNotFoundError as ex:
        print("ResourceNotFoundError:", ex.message)

列出共享和快照

可以为特定的共享列出所有快照。

def list_shares_snapshots(self, connection_string):
    try:
        # Create a ShareServiceClient from a connection string
        service_client = ShareServiceClient.from_connection_string(connection_string)

        # List the shares in the file service
        shares = list(service_client.list_shares(include_snapshots=True))

        for share in shares:
            if (share["snapshot"]):
                print("Share:", share["name"], "Snapshot:", share["snapshot"])
            else:
                print("Share:", share["name"])

    except ResourceNotFoundError as ex:
        print("ResourceNotFoundError:", ex.message)

浏览共享快照

可以浏览每个共享快照来检索相应时间点的文件和目录。

def browse_snapshot_dir(self, connection_string, share_name, snapshot_time, dir_name):
    try:
        # Create a ShareClient from a connection string
        snapshot = ShareClient.from_connection_string(
            conn_str=connection_string, share_name=share_name, snapshot=snapshot_time)

        print("Snapshot:", snapshot_time)

        for item in list(snapshot.list_directories_and_files(dir_name)):
            if item["is_directory"]:
                print("Directory:", item["name"])
            else:
                print("File:", dir_name + "/" + item["name"])

    except ResourceNotFoundError as ex:
        print("ResourceNotFoundError:", ex.message)

从共享快照获取文件

可以从共享快照下载文件。 这使你可以还原文件的早期版本。

def download_snapshot_file(self, connection_string, share_name, snapshot_time, dir_name, file_name):
    try:
        # Build the remote path
        source_file_path = dir_name + "/" + file_name

        # Add a prefix to the local filename to 
        # indicate it's a file from a snapshot
        dest_file_name = "SNAPSHOT-" + file_name

        # Create a ShareFileClient from a connection string
        snapshot_file_client = ShareFileClient.from_connection_string(
            conn_str=connection_string, share_name=share_name, 
            file_path=source_file_path, snapshot=snapshot_time)

        print("Downloading to:", dest_file_name)

        # Open a file for writing bytes on the local system
        with open(dest_file_name, "wb") as data:
            # Download the file from Azure into a stream
            stream = snapshot_file_client.download_file()
            # Write the stream to the local file
            data.write(stream.readall())

    except ResourceNotFoundError as ex:
        print("ResourceNotFoundError:", ex.message)

删除单个共享快照

可以删除单个共享快照。

def delete_snapshot(self, connection_string, share_name, snapshot_time):
    try:
        # Create a ShareClient for a snapshot
        snapshot_client = ShareClient.from_connection_string(conn_str=connection_string, share_name=share_name, snapshot=snapshot_time)

        print("Deleting snapshot:", snapshot_time)

        # Delete the snapshot
        snapshot_client.delete_share()

    except ResourceNotFoundError as ex:
        print("ResourceNotFoundError:", ex.message)

删除文件

若要删除文件,请调用 delete_file

def delete_azure_file(self, connection_string, share_name, file_path):
    try:
        # Create a ShareFileClient from a connection string
        file_client = ShareFileClient.from_connection_string(
            connection_string, share_name, file_path)

        print("Deleting file:", share_name + "/" + file_path)

        # Delete the file
        file_client.delete_file()

    except ResourceNotFoundError as ex:
        print("ResourceNotFoundError:", ex.message)

共享快照存在时,删除共享

若要删除包含快照的共享,请调用带有 delete_snapshots=Truedelete_share

def delete_share(self, connection_string, share_name):
    try:
        # Create a ShareClient from a connection string
        share_client = ShareClient.from_connection_string(
            connection_string, share_name)

        print("Deleting share:", share_name)

        # Delete the share and snapshots
        share_client.delete_share(delete_snapshots=True)

    except ResourceNotFoundError as ex:
        print("ResourceNotFoundError:", ex.message)

后续步骤

了解如何使用 Python 操作 Azure 文件后,请单击以下链接了解更多信息。