如何用Python从Azure多容器下载对应每日特定Blob文件

我是Python新手，需要从Azure存储中每日创建的日期命名容器（如01092022）里，下载对应名称的xlsx格式Blob文件（如p.01092022.xlsx）。现有代码仅能处理单个容器，请问如何遍历所有目标容器并下载对应文件？

尝试的代码 #

# download_blobs.py
# Python program to bulk download blob files from azure storage
# Uses latest python SDK() for Azure blob storage
# Requires python 3.6 or above
import os
from azure.storage.blob import BlobServiceClient, BlobClient
from azure.storage.blob import ContentSettings, ContainerClient
 
# IMPORTANT: Replace connection string with your storage account connection string
# Usually starts with DefaultEndpointsProtocol=https;...
MY_CONNECTION_STRING = "my_conection_string"
 
# Replace with blob container
MY_BLOB_CONTAINER = "^092022"
 
# Replace with the local folder where you want files to be downloaded
LOCAL_BLOB_PATH = "a_local_path"

# Replace with the blob to download
BLOB_NAME = "^xlsx'"

class AzureBlobFileDownloader:
  def __init__(self):
    print("Intializing AzureBlobFileDownloader")
 
    # Initialize the connection to Azure storage account
    self.blob_service_client =  BlobServiceClient.from_connection_string(MY_CONNECTION_STRING)
    self.my_container = self.blob_service_client.get_container_client(MY_BLOB_CONTAINER)
 
 
  def save_blob(self,file_name,file_content):
    # Get full path to the file
    download_file_path = os.path.join(LOCAL_BLOB_PATH, file_name)
 
    # for nested blobs, create local path as well!
    os.makedirs(os.path.dirname(download_file_path), exist_ok=True)
 
    with open(download_file_path, "wb") as file:
      file.write(file_content)
 
  def download_all_blobs_in_container(self):
    my_blobs = self.my_container.list_blobs(BLOB_NAME)
    for blob in my_blobs:
      print(blob.name)
      bytes = self.my_container.get_blob_client(blob).download_blob().readall()
      self.save_blob(blob.name, bytes)
 
# Initialize class and upload files
azure_blob_file_downloader = AzureBlobFileDownloader()
azure_blob_file_downloader.download_all_blobs_in_container()

要实现遍历所有日期命名容器并下载对应文件，需要调整代码逻辑，完成容器筛选、目标Blob定位、批量下载三个核心步骤，修改后的代码如下：

import os
import re
from azure.storage.blob import BlobServiceClient

# 替换为你的存储账户连接字符串
MY_CONNECTION_STRING = "your_connection_string"
# 本地文件下载路径
LOCAL_BLOB_PATH = "your_local_path"
# 日期容器的正则匹配规则（DDMMYYYY格式）
DATE_CONTAINER_PATTERN = r'^\d{8}$'
# Blob文件名固定前缀
BLOB_PREFIX = "p."

class AzureBlobFileDownloader:
    def __init__(self):
        print("初始化AzureBlobFileDownloader")
        self.blob_service_client = BlobServiceClient.from_connection_string(MY_CONNECTION_STRING)

    def save_blob(self, container_name, file_name, file_content):
        # 按容器名创建本地子目录，区分不同日期的文件
        download_file_path = os.path.join(LOCAL_BLOB_PATH, container_name, file_name)
        os.makedirs(os.path.dirname(download_file_path), exist_ok=True)
        
        with open(download_file_path, "wb") as file:
            file.write(file_content)
        print(f"已下载: {download_file_path}")

    def download_target_blobs(self):
        # 遍历存储账户下所有容器
        containers = self.blob_service_client.list_containers()
        for container in containers:
            container_name = container.name
            # 筛选出符合DDMMYYYY格式的日期容器
            if re.match(DATE_CONTAINER_PATTERN, container_name):
                print(f"开始处理容器: {container_name}")
                container_client = self.blob_service_client.get_container_client(container_name)
                # 构造目标Blob文件名
                target_blob_name = f"{BLOB_PREFIX}{container_name}.xlsx"
                try:
                    blob_client = container_client.get_blob_client(target_blob_name)
                    # 检查Blob是否存在，存在则下载
                    if blob_client.exists():
                        file_content = blob_client.download_blob().readall()
                        self.save_blob(container_name, target_blob_name, file_content)
                    else:
                        print(f"容器{container_name}中未找到目标文件: {target_blob_name}")
                except Exception as e:
                    print(f"处理容器{container_name}出错: {str(e)}")

if __name__ == "__main__":
    downloader = AzureBlobFileDownloader()
    downloader.download_target_blobs()

关键修改说明 #

• 容器筛选：用正则表达式DATE_CONTAINER_PATTERN精准匹配DDMMYYYY格式的容器名，避免处理无关容器
• 批量遍历：新增遍历所有容器的逻辑，对每个符合条件的容器单独处理
• 文件定位：根据容器名构造对应Blob文件名，确保下载的是与容器日期匹配的xlsx文件
• 本地存储优化：按容器名创建本地子目录，避免不同日期的文件互相覆盖
• 异常处理：添加捕获异常的逻辑，避免单个容器处理失败导致整个程序终止

内容的提问来源于stack exchange，提问作者David Valdera