[Cleanup] storage/s3-sdk: Adds docstrings, return value instead of print

storage/s3-sdk/list_gcs_buckets.py

@@ -21,11 +21,19 @@
 
 
 def list_gcs_buckets(google_access_key_id, google_access_key_secret):
-    """Lists all GCS buckets using boto3 SDK"""
-    # Create a new client and do the following:
-    # 1. Change the endpoint URL to use the
-    #    Google Cloud Storage XML API endpoint.
-    # 2. Use Cloud Storage HMAC Credentials.
+    """Lists all Cloud Storage buckets using AWS SDK for Python (boto3)
+    Positional arguments:
+    google_access_key_id          -- hash-based message authentication code (HMAC) access ID
+    google_access_key_secret      -- HMAC access secret
+
+    Returned value is a list of strings, one for each bucket name.
+
+    To use this sample:
+    1. Create a Cloud Storage HMAC key: https://cloud.google.com/storage/docs/authentication/managing-hmackeys#create
+    2. Change endpoint_url to a Google Cloud Storage XML API endpoint.
+
+    To learn more about HMAC: https://cloud.google.com/storage/docs/authentication/hmackeys#overview
+    """
     client = boto3.client(
         "s3",
         region_name="auto",
@@ -37,10 +45,11 @@ def list_gcs_buckets(google_access_key_id, google_access_key_secret):
     # Call GCS to list current buckets
     response = client.list_buckets()
 
-    # Print bucket names
-    print("Buckets:")
+    # Return list of bucket names
+    results = []
     for bucket in response["Buckets"]:
-        print(bucket["Name"])
+        results.append(bucket["Name"])
+    return results
 
 
 # [END storage_s3_sdk_list_buckets]

storage/s3-sdk/list_gcs_objects.py

@@ -21,12 +21,20 @@
 
 
 def list_gcs_objects(google_access_key_id, google_access_key_secret, bucket_name):
-    """Lists GCS objects using boto3 SDK"""
-    # Create a new client and do the following:
-    # 1. Change the endpoint URL to use the
-    #    Google Cloud Storage XML API endpoint.
-    # 2. Use Cloud Storage HMAC Credentials.
+    """Lists all Cloud Storage objects using AWS SDK for Python (boto3)
+    Positional arguments:
+    google_access_key_id          -- hash-based message authentication code (HMAC) access ID
+    google_access_key_secret      -- HMAC access secret
+    bucket_name                   -- name of Cloud Storage bucket
 
+    Returned value is a list of strings, one for each object in the bucket.
+
+    To use this sample:
+    1. Create a Cloud Storage HMAC key: https://cloud.google.com/storage/docs/authentication/managing-hmackeys#create
+    2. Change endpoint_url to a Google Cloud Storage XML API endpoint.
+
+    To learn more about HMAC: https://cloud.google.com/storage/docs/authentication/hmackeys#overview
+    """
     client = boto3.client(
         "s3",
         region_name="auto",
@@ -38,10 +46,11 @@ def list_gcs_objects(google_access_key_id, google_access_key_secret, bucket_name
     # Call GCS to list objects in bucket_name
     response = client.list_objects(Bucket=bucket_name)
 
-    # Print object names
-    print("Objects:")
+    # Return list of object names in bucket
+    results = []
     for blob in response["Contents"]:
-        print(blob["Key"])
+        results.append(blob["Key"])
+    return results
 
 
 # [END storage_s3_sdk_list_objects]

storage/s3-sdk/noxfile_config.py

@@ -35,13 +35,13 @@ def get_service_account_email():
 TEST_CONFIG_OVERRIDE = {
     # A dictionary you want to inject into your test. Don't put any
     # secrets here. These values will override predefined values.
-    'envs': {
-        'HMAC_KEY_TEST_SERVICE_ACCOUNT': get_service_account_email(),
+    "envs": {
+        "HMAC_KEY_TEST_SERVICE_ACCOUNT": get_service_account_email(),
         # Some tests can not use multiple projects because of several reasons:
         # 1. The new projects is enforced to have the
         # 'constraints/iam.disableServiceAccountKeyCreation' policy.
         # 2. The new projects buckets need to have universal permission model.
         # For those tests, we'll use the original project.
-        'MAIN_GOOGLE_CLOUD_PROJECT': 'python-docs-samples-tests'
+        "MAIN_GOOGLE_CLOUD_PROJECT": "python-docs-samples-tests",
     },
 }

storage/s3-sdk/s3_sdk_test.py

@@ -69,24 +69,20 @@ def test_blob(test_bucket):
 # to 15s.
 @backoff.on_exception(backoff.constant, ClientError, interval=1, max_time=15)
 def test_list_buckets(capsys, hmac_fixture, test_bucket):
-    list_gcs_buckets.list_gcs_buckets(
+    results = list_gcs_buckets.list_gcs_buckets(
         google_access_key_id=hmac_fixture[0].access_id,
         google_access_key_secret=hmac_fixture[1],
     )
-    out, _ = capsys.readouterr()
-    assert "Buckets:" in out
-    assert test_bucket.name in out
+    assert test_bucket.name in results
 
 
 # Retry request because the created key may not be fully propagated for up
 # to 15s.
 @backoff.on_exception(backoff.constant, ClientError, interval=1, max_time=15)
 def test_list_blobs(capsys, hmac_fixture, test_bucket, test_blob):
-    list_gcs_objects.list_gcs_objects(
+    result = list_gcs_objects.list_gcs_objects(
         google_access_key_id=hmac_fixture[0].access_id,
         google_access_key_secret=hmac_fixture[1],
         bucket_name=test_bucket.name,
     )
-    out, _ = capsys.readouterr()
-    assert "Objects:" in out
-    assert test_blob.name in out
+    assert test_blob.name in result