Change to basicConfig() to fix #1021.

Lib/logging/__init__.py

@@ -1247,7 +1247,7 @@ def basicConfig(**kwargs):
         hdlr.setFormatter(fmt)
         root.addHandler(hdlr)
         level = kwargs.get("level")
-        if level:
+        if level is not None:
             root.setLevel(level)
 
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