Clean up batch delete sample (Azure#15898)

* cleaned up batch delete sample

* fixed spacing

sdk/storage/azure-storage-blob/samples/blob_samples_batch_delete_blobs.py

@@ -1,4 +1,5 @@
-from azure.storage.blob import BlobServiceClient, ContainerClient
+from azure.core.exceptions import ResourceExistsError
+from azure.storage.blob import BlobServiceClient
 import os
 
 """
@@ -13,27 +14,29 @@
 
 SOURCE_FOLDER = "./sample-blobs/"
 
+
 def batch_delete_blobs_sample(local_path):
-	# Set the connection string and container name values to initialize the Container Client
+    # Set the connection string and container name values to initialize the Container Client
     connection_string = os.getenv('AZURE_STORAGE_CONNECTION_STRING')
 
     blob_service_client = BlobServiceClient.from_connection_string(conn_str=connection_string)
-	# Create a ContainerClient to use the batch_delete function on a Blob Container
+    # Create a ContainerClient to use the batch_delete function on a Blob Container
     container_client = blob_service_client.get_container_client("mycontainername")
     try:
         container_client.create_container()
     except ResourceExistsError:
         pass
-	# Upload blobs
+    # Upload blobs
     for filename in os.listdir(local_path):
         with open(local_path+filename, "rb") as data:
             container_client.upload_blob(name=filename, data=data, blob_type="BlockBlob")
 
-	# List blobs in storage account
+    # List blobs in storage account
     blob_list = [b.name for b in list(container_client.list_blobs())]
-
-	# Delete blobs
+    
+    # Delete blobs
     container_client.delete_blobs(*blob_list)
 
-if __name__  == '__main__':
+if __name__ == '__main__':
     batch_delete_blobs_sample(SOURCE_FOLDER)
+