Async blob code samples (#6728)

* working on async blob samples

* fix name

* adds start copy blob sample and fixes typos

* add async suffix to test samples

* update rtypes to async

* update readme

* update readme link to docs

* add copy blob to example list

Author: kristapratico

sdk/storage/azure-storage-blob/README.md

@@ -9,7 +9,7 @@ Blob storage is ideal for:
 * Storing data for backup and restore, disaster recovery, and archiving
 * Storing data for analysis by an on-premises or Azure-hosted service
 
-[Source code](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/azure/storage/blob) | [Package (PyPi)](https://pypi.org/project/azure-storage-blob/) | [API reference documentation](https://docs.microsoft.com/rest/api/storageservices/blob-service-rest-api) | [Product documentation](https://docs.microsoft.com/azure/storage/) | [Samples](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests)
+[Source code](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/azure/storage/blob) | [Package (PyPi)](https://pypi.org/project/azure-storage-blob/) | [API reference documentation](https://azure.github.io/azure-sdk-for-python/ref/azure.storage.blob.html) | [Product documentation](https://docs.microsoft.com/azure/storage/) | [Samples](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests)
 
 
 ## Getting started
@@ -124,6 +124,17 @@ blob = BlobClient.from_connection_string("my_connection_string", container="myco
 with open("./SampleSource.txt", "rb") as data:
     blob.upload_blob(data)
 ```
+Use the async client to upload a blob to your container.
+
+```python
+from azure.storage.blob.aio import BlobClient
+
+blob = BlobClient.from_connection_string("my_connection_string", container="mycontainer", blob="my_blob")
+
+with open("./SampleSource.txt", "rb") as data:
+    await blob.upload_blob(data)
+```
+
 ### Downloading a blob
 Download a blob from your container.
 
@@ -137,8 +148,21 @@ with open("./BlockDestination.txt", "wb") as my_blob:
     my_blob.writelines(blob_data.content_as_bytes())
 ```
 
+Download a blob asynchronously.
+
+```python
+from azure.storage.blob.aio import BlobClient
+
+blob = BlobClient.from_connection_string("my_connection_string", container="mycontainer", blob="my_blob")
+
+with open("./BlockDestination.txt", "wb") as my_blob:
+    stream = await blob.download_blob()
+    data = await stream.content_as_bytes()
+    my_blob.write(data)
+```
+
 ### Enumerating blobs
-List the blob in your container.
+List the blobs in your container.
 
 ```python
 from azure.storage.blob import ContainerClient
@@ -150,6 +174,19 @@ for blob in blob_list:
     print(blob.name + '\n')
 ```
 
+List the blobs asynchronously.
+
+```python
+from azure.storage.blob.aio import ContainerClient
+
+container = ContainerClient.from_connection_string("my_connection_string", container="mycontainer")
+
+blob_list = [] 
+async for blob in container.list_blobs():
+    blob_list.append(blob)
+print(blob_list)
+```
+
 ## Troubleshooting
 Storage Blob clients raise exceptions defined in [Azure Core](https://github.com/Azure/azure-sdk-for-python/blob/master/sdk/core/azure-core/docs/exceptions.md).
 
@@ -163,27 +200,27 @@ Get started with our [Blob samples](https://github.com/Azure/azure-sdk-for-pytho
 
 Several Storage Blobs Python SDK samples are available to you in the SDK's GitHub repository. These samples provide example code for additional scenarios commonly encountered while working with Storage Blobs:
 
-* [`test_blob_samples_hello_world.py`](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_hello_world.py) - Examples for common Storage Blob tasks:
+* [`test_blob_samples_hello_world.py`](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_hello_world.py) ([async version](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_hello_world_async.py)) - Examples for common Storage Blob tasks:
     * Set up a container
     * Create a block, page, or append blob
     * Upload blobs
     * Download blobs
     * Delete blobs
 
-* [`test_blob_samples_authentication.py`](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_authentication.py) - Examples for authenticating and creating the client:
+* [`test_blob_samples_authentication.py`](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_authentication.py) ([async version](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_authentication_async.py)) - Examples for authenticating and creating the client:
     * From a connection string
     * From a shared access key
     * From a shared access signature token
     * From active directory
 
-* [`test_blob_samples_service.py`](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_service.py) - Examples for interacting with the blob service:
+* [`test_blob_samples_service.py`](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_service.py) ([async version](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_service_async.py)) - Examples for interacting with the blob service:
     * Get account information
     * Get and set service properties
     * Get service statistics
     * Create, list, and delete containers
     * Get the Blob or Container client
 
-* [`test_blob_samples_containers.py`](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_containers.py) - Examples for interacting with containers:
+* [`test_blob_samples_containers.py`](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_containers.py) ([async version](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_containers_async.py)) - Examples for interacting with containers:
     * Create a container and delete containers
     * Set metadata on containers
     * Get container properties
@@ -192,12 +229,13 @@ Several Storage Blobs Python SDK samples are available to you in the SDK's GitHu
     * Upload, list, delete blobs in container
     * Get the blob client to interact with a specific blob
 
-* [`test_blob_samples_common.py`](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_common.py) - Examples common to all types of blobs:
+* [`test_blob_samples_common.py`](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_common.py) ([async version](https://github.com/Azure/azure-sdk-for-python/tree/master/sdk/storage/azure-storage-blob/tests/test_blob_samples_common_async.py)) - Examples common to all types of blobs:
     * Create a snapshot
     * Delete a blob snapshot
     * Soft delete a blob
     * Undelete a blob
     * Acquire a lease on a blob
+    * Copy a blob from a URL
 
 
 ### Additional documentation