STORAGEACCOUNTURL= "https://cchbcaadls2prod.blob.core.windows.net/cchbc"
STORAGEACCOUNTKEY= "J0OGUd0Ac+N8TJbptBLmnQ0okp4yqIpaynmHjBkIYnsJYIiC9mUBL6GrH+QQNSWewS3/7i7CSHckZaWvH3HIog=="
LOCALFILENAME= <local_file_name>
CONTAINERNAME= <container_name>
BLOBNAME= <blob_name>

#download from blob
t1=time.time()
blob_service_client_instance = BlobServiceClient(account_url=STORAGEACCOUNTURL, credential=STORAGEACCOUNTKEY)
print("\nListing blobs...")

# List the blobs in the container
blob_list = container_client.list_blobs()
for blob in blob_list:
    print("\t" + blob.name)
blob_client_instance = blob_service_client_instance.get_blob_client(CONTAINERNAME, BLOBNAME, snapshot=None)
with open(LOCALFILENAME, "wb") as my_blob:
    blob_data = blob_client_instance.download_blob()
    blob_data.readinto(my_blob)
t2=time.time()
print(("It takes %s seconds to download "+BLOBNAME) % (t2 - t1))