Add propagate=False opt to basic_logger()

ska_helpers/logging.py

@@ -3,7 +3,12 @@
 __all__ = ["basic_logger"]
 
 
-def basic_logger(name, format="%(asctime)s %(funcName)s: %(message)s", **kwargs):
+def basic_logger(
+    name,
+    format="%(asctime)s %(funcName)s: %(message)s",
+    propagate=False,
+    **kwargs
+):
     """Create logger ``name`` using logging.basicConfig.
 
     This is a thin wrapper around logging.basicConfig, except:
@@ -16,14 +21,20 @@ def basic_logger(name, format="%(asctime)s %(funcName)s: %(message)s", **kwargs)
       It will probably work but it is not guaranteed.
 
     This function does nothing if the ``name`` logger already has handlers
-    configured, unless the keyword argument *force* is set to ``True``.
+    configured, unless the keyword argument ``force`` is set to ``True``.
     It is a convenience method intended to do one-shot creation of a logger.
 
     The default behaviour is to create a StreamHandler which writes to
     ``sys.stderr``, set a formatter using the format string ``"%(asctime)s
     %(funcName)s: %(message)s"``, and add the handler to the ``name`` logger
     with a level of WARNING.
 
+    By default the created logger will not propagate to parent loggers. This
+    is to prevent unexpected logging from other packages that set up a root
+    logger. To propagate to parent loggers, set ``propagate=True``. See
+    https://docs.python.org/3/howto/logging.html#logging-flow, in particular
+    how the log level of parent loggers is ignored in message handling.
+
     Example::
 
       # In __init__.py for a package or in any module
@@ -72,6 +83,7 @@ def basic_logger(name, format="%(asctime)s %(funcName)s: %(message)s", **kwargs)
 
     :param name: str, logger name
     :param format: str, format string for handler
+    :param propagate: bool, propagate to parent loggers (default=False)
     :param **kwargs: other keyword arguments for logging.basicConfig
     :returns: Logger object
     """
@@ -94,4 +106,6 @@ def basic_logger(name, format="%(asctime)s %(funcName)s: %(message)s", **kwargs)
     finally:
         logging.root = root
 
+    logger.propagate = propagate
+
     return logger