Configure logging handlers before submodule imports

- Fix #474
- Fix #475

smart_open/__init__.py

@@ -25,6 +25,10 @@
 import logging
 from smart_open import version
 
+logger = logging.getLogger(__name__)
+if len(logger.handlers) == 0:
+    logger.addHandler(logging.NullHandler())
+
 from .smart_open_lib import open, parse_uri, smart_open, register_compressor
 from .s3 import iter_bucket as s3_iter_bucket
 
@@ -36,8 +40,4 @@
     'smart_open',
 ]
 
-
 __version__ = version.__version__
-
-logger = logging.getLogger(__name__)
-logger.addHandler(logging.NullHandler())