How to Download/Upload Files from Azure Blob using Python in Spyder/Anaconda-CodePudding

I am new to Azure. I created a Blob Storage today. I am trying to run some Python code that I found online, to download files fro this Blob Container. Here is the code that I am testing.

# 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 = "DefaultEndpointsProtocol=https;AccountName=ryanpythonstorage;AccountKey=my_account_key;EndpointSuffix=core.windows.net"

# Replace with blob container
MY_BLOB_CONTAINER = "ryanpythonstorage" #copied from Access Keys
 
# Replace with the local folder where you want files to be downloaded
LOCAL_BLOB_PATH = "C:\\Users\\ryans\\Desktop\\blob\\"
 
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()
    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()

Here is the result that I see when I run the code.

Intializing AzureBlobFileDownloader
Traceback (most recent call last):

  File "C:\Users\ryans\AppData\Local\Temp\ipykernel_14020\3010845424.py", line 37, in <module>
    azure_blob_file_downloader.download_all_blobs_in_container()

  File "C:\Users\ryans\AppData\Local\Temp\ipykernel_14020\3010845424.py", line 30, in download_all_blobs_in_container
    for blob in my_blobs:

  File "C:\Users\ryans\anaconda3\lib\site-packages\azure\core\paging.py", line 129, in __next__
    return next(self._page_iterator)

  File "C:\Users\ryans\anaconda3\lib\site-packages\azure\core\paging.py", line 76, in __next__
    self._response = self._get_next(self.continuation_token)

  File "C:\Users\ryans\anaconda3\lib\site-packages\azure\storage\blob\_list_blobs_helper.py", line 79, in _get_next_cb
    process_storage_error(error)

  File "C:\Users\ryans\anaconda3\lib\site-packages\azure\storage\blob\_shared\response_handlers.py", line 177, in process_storage_error
    exec("raise error from None")   # pylint: disable=exec-used # nosec

  File "<string>", line 1, in <module>

  File "C:\Users\ryans\anaconda3\lib\site-packages\azure\storage\blob\_list_blobs_helper.py", line 72, in _get_next_cb
    return self._command(

  File "C:\Users\ryans\anaconda3\lib\site-packages\azure\storage\blob\_generated\operations\_container_operations.py", line 1479, in list_blob_flat_segment
    map_error(status_code=response.status_code, response=response, error_map=error_map)

  File "C:\Users\ryans\anaconda3\lib\site-packages\azure\core\exceptions.py", line 105, in map_error
    raise error

ResourceNotFoundError: The specified container does not exist.
RequestId:4d2df1c1-a01e-008b-4209-21e493000000
Time:2022-02-13T18:44:14.1140999Z
ErrorCode:ContainerNotFound
Content: <?xml version="1.0" encoding="utf-8"?><Error><Code>ContainerNotFound</Code><Message>The specified container does not exist.
RequestId:4d2df1c1-a01e-008b-4209-21e493000000
Time:2022-02-13T18:44:14.1140999Z</Message></Error>

Ultimately, I want to be able to do two things:

download files from my Blob to my local machine
upload files from my local machine to my Blob.

CodePudding user response：

The error message is that it cannot find the container. It could be:

A problem with rights (connection string)
A problem with the container name

In MY_CONNECTION_STRING and MY_BLOB_CONTAINER the name of your account and the name of your container is the same. If one of these is incorrect it would explain the error.

CodePudding user response：

Here is my final working code.

import os
import uuid
import sys
from azure.storage.blob import BlockBlobService, PublicAccess

try:
    # Create the BlockBlobService that is used to call the Blob service for the storage account
    blob_service_client = BlockBlobService(account_name='your_account_name_goes_here', account_key='your_account_key_goes_here')
    
    # Create a container called 'quickstartblobs'.
    container_name = 'your_container_name_goes_here'
    blob_service_client.create_container(container_name)
    
    # Set the permission so the blobs are public.
    blob_service_client.set_container_acl(container_name, public_access=PublicAccess.Container)
    
    # Create Sample folder if it not exists, and create a file in folder Sample to test the upload and download.
    local_path = os.path.expanduser('C:\\Users\\ryans\\Desktop\\blob\\')
        
    local_file_name  = 'charges.csv'
    #local_file_name = "QuickStart_"   str(uuid.uuid4())   ".txt"
    full_path_to_file = os.path.join(local_path, local_file_name)

    print("Temp file = "   full_path_to_file)
    print("\nUploading to Blob storage as blob"   local_file_name)
    
    # Upload the created file, use local_file_name for the blob name
    blob_service_client.create_blob_from_path(container_name, local_file_name, full_path_to_file)
    
    # List the blobs in the container
    print("\nList blobs in the container")
    generator = blob_service_client.list_blobs(container_name)
    
    for blob in generator:
        print("\t Blob name: "   blob.name)

except Exception as e:
    print(e)
    
##############################################################################################


import os
import uuid
import sys
from azure.storage.blob import BlockBlobService, PublicAccess

try:
    
    local_path = os.path.expanduser('C:\\Users\\ryans\\Desktop\\blob\\')
    container_name = 'your_container_name_goes_here'
    local_file_name  = 'charges.csv'
    
    # Download the blob(s).
    # Add '_DOWNLOADED' as prefix to '.txt' so you can see both files in Documents.
    full_path_to_file = os.path.join(local_path, local_file_name)
    print("\nDownloading blob to "   full_path_to_file)
    blob_service_client.get_blob_to_path(container_name, local_file_name, full_path_to_file)
    
    #sys.stdout.write("Sample finished running. When you hit <any key>, the sample will be deleted and the sample application will exit.")
    sys.stdout.flush()
    input()

except Exception as e:
    print(e)

This link was a great resource for me.

https://github.com/Azure-Samples/azure-sdk-for-python-storage-blob-upload-download/blob/master/example.py