set default level of logger "gino" to WARNING

Fixes #710

Author: fantix

src/gino/__init__.py

@@ -1,9 +1,15 @@
+import logging
+
 from .api import Gino  # NOQA
 from .bakery import Bakery
 from .engine import GinoEngine, GinoConnection  # NOQA
 from .exceptions import *  # NOQA
 from .strategies import GinoStrategy  # NOQA
 
+rootlogger = logging.getLogger("gino")
+if rootlogger.level == logging.NOTSET:
+    rootlogger.setLevel(logging.WARN)
+
 
 def create_engine(*args, **kwargs):
     """

tests/test_engine.py

@@ -100,20 +100,26 @@ async def test_compile(engine):
 
 
 async def test_logging(mocker):
-    mocker.patch("logging.Logger._log")
-    sql = "SELECT NOW() AS test_logging"
-
-    e = await create_engine(PG_URL, echo=False)
-    await e.scalar(sql)
-    await e.close()
-    # noinspection PyProtectedMember,PyUnresolvedReferences
-    logging.Logger._log.assert_not_called()
-
-    e = await create_engine(PG_URL, echo=True)
-    await e.scalar(sql)
-    await e.close()
-    # noinspection PyProtectedMember,PyUnresolvedReferences
-    logging.Logger._log.assert_any_call(logging.INFO, sql, ())
+    orig_level = logging.root.level
+    # #710: the level of logger "gino" should not be NOTSET, thus not affected by root
+    logging.root.setLevel(logging.DEBUG)
+    try:
+        mocker.patch("logging.Logger._log")
+        sql = "SELECT NOW() AS test_logging"
+
+        e = await create_engine(PG_URL, echo=False)
+        await e.scalar(sql)
+        await e.close()
+        # noinspection PyProtectedMember,PyUnresolvedReferences
+        logging.Logger._log.assert_not_called()
+
+        e = await create_engine(PG_URL, echo=True)
+        await e.scalar(sql)
+        await e.close()
+        # noinspection PyProtectedMember,PyUnresolvedReferences
+        logging.Logger._log.assert_any_call(logging.INFO, sql, ())
+    finally:
+        logging.root.setLevel(orig_level)
 
 
 async def test_set_isolation_level():