Requested changes

scrapy/extensions/feedexport.py

@@ -96,21 +96,22 @@ class S3FeedStorage(BlockingFeedStorage):
     def __init__(self, uri, access_key=None, secret_key=None):
         # BEGIN Backwards compatibility for initialising without keys (and
         # without using from_crawler)
-        from scrapy.conf import settings
         no_defaults = access_key is None and secret_key is None
-        if no_defaults and ('AWS_ACCESS_KEY_ID' in settings or
-                            'AWS_SECRET_ACCESS_KEY' in settings):
-            import warnings
-            from scrapy.exceptions import ScrapyDeprecationWarning
-            warnings.warn(
-                "Initialising `scrapy.extensions.feedexport.S3FeedStorage` "
-                "without AWS keys is deprecated. Please supply credentials or "
-                "use the `from_crawler()` constructor.",
-                category=ScrapyDeprecationWarning,
-                stacklevel=2
-            )
-            access_key = settings['AWS_ACCESS_KEY_ID']
-            secret_key = settings['AWS_SECRET_ACCESS_KEY']
+        if no_defaults:
+            from scrapy.conf import settings
+            if 'AWS_ACCESS_KEY_ID' in settings or 'AWS_SECRET_ACCESS_KEY' in settings:
+                import warnings
+                from scrapy.exceptions import ScrapyDeprecationWarning
+                warnings.warn(
+                    "Initialising `scrapy.extensions.feedexport.S3FeedStorage` "
+                    "without AWS keys is deprecated. Please supply credentials or "
+                    "use the `from_crawler()` constructor.",
+                    category=ScrapyDeprecationWarning,
+                    stacklevel=2
+                )
+                access_key = settings['AWS_ACCESS_KEY_ID']
+                secret_key = settings['AWS_SECRET_ACCESS_KEY']
+        # END Backwards compatibility
         u = urlparse(uri)
         self.bucketname = u.hostname
         self.access_key = u.username or access_key

scrapy/utils/misc.py

@@ -118,6 +118,7 @@ def rel_has_nofollow(rel):
     """Return True if link rel attribute has nofollow type"""
     return True if rel is not None and 'nofollow' in rel.split() else False
 
+
 def create_instance(objcls, settings, crawler, *args, **kwargs):
     """Construct a class instance using its ``from_crawler`` or
     ``from_settings`` constructors, if available.

tests/test_feedexport.py

@@ -173,7 +173,9 @@ class S3FeedStorageTest(unittest.TestCase):
         uri = os.environ.get('S3_TEST_FILE_URI')
         if not uri:
             raise unittest.SkipTest("No S3 URI available for testing")
-        storage = S3FeedStorage(uri, Settings())
+        access_key = os.environ.get('AWS_ACCESS_KEY_ID')
+        secret_key = os.environ.get('AWS_SECRET_ACCESS_KEY')
+        storage = S3FeedStorage(uri, access_key, secret_key)
         verifyObject(IFeedStorage, storage)
         file = storage.open(scrapy.Spider("default"))
         expected_content = b"content: \xe2\x98\x83"