lf_logger_config_example.json : sandbox example for using logging config

lf_logger_config_test.py : example program
lf_sublogger.py : included module sample
lf_sublogger_2.py : included an inherited module same.

This code is for becomming familiar with the logging module

py-scripts/sandbox/lf_logger_config_example.json

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+{
+    "version": 1,
+    "disable_existing_loggers": false,
+    "formatters": {
+        "simple": {
+            "format": "%(created)-16f %(name)-16s %(levelname)-12s %(lineno)-6s %(funcName)-16s [%(module)s]:  %(message)s"
+        },
+        "extra": {
+            "format":"%(asctime)-16s %(name)-8s %(filename)-12s %(lineno)-6s %(funcName)-16s %(levelname)-8s [%(module)s]: %(message)s",
+                 "datefmt":"%m-%d %H:%M:%S"},
+        "extra2": {
+            "format":"%(created)f %(name)-8s %(filename)-12s %(lineno)-6s %(funcName)-16s %(levelname)-8s [%(module)s]: %(message)s",
+                    "datefmt":"%m-%d %H:%M:%S"}
+    },
+
+    "handlers": {
+        "console": {
+            "class": "logging.StreamHandler",
+            "level": "DEBUG",
+            "formatter": "extra2",
+            "stream": "ext://sys.stdout"
+        },
+        "file": {
+            "class": "logging.FileHandler",
+            "level": "DEBUG",
+            "formatter": "extra2",
+            "filename": "test.log",
+            "mode": "w",
+            "encoding": "utf-8"
+        }
+    },
+    "loggers": {
+        "py-scripts.sandbox.lf_sublogger_2":{
+            "level": "DEBUG",
+            "handlers": ["console", "file"],
+            "propagate": false
+        },
+        "py-json.LANforge.LFRequest":{
+            "level": "CRITICAL",
+            "handlers": ["console", "file"],
+            "propagate": false
+        },
+        "__main__":{
+            "level": "DEBUG",
+            "handlers": ["console", "file"],
+            "propagate": false
+        }
+    },        
+    "root": {
+        "level": "DEBUG",
+        "handlers": ["console", "file"],
+        "propagate": false
+    }
+}

py-scripts/sandbox/lf_logger_config_test.py

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+#!/usr/bin/env python3
+
+import sys
+import os
+import logging
+import importlib
+
+import time
+import importlib
+
+if sys.version_info[0] != 3:
+    print("This script requires Python 3")
+    exit(1)
+
+sys.path.append(os.path.join(os.path.abspath(__file__ + "../../../../")))
+lf_logger_config = importlib.import_module("py-scripts.lf_logger_config")
+lf_sublogger = importlib.import_module("py-scripts.sandbox.lf_sublogger")
+
+
+logger = logging.getLogger(__name__)
+
+# example from
+# https://gist.github.com/timss/8f03ae681256f21e25f8b0a16327c26c
+
+# another example for using JSON config
+# https://fangpenlin.com/posts/2012/08/26/good-logging-practice-in-python/
+
+# loggers hierarchy and log record propagation
+# https://stackoverflow.com/questions/50301613/logging-in-python-with-json-configuration-things-get-logged-more-than-once
+
+# root logger compared to named logger
+# https://stackoverflow.com/questions/4150148/logging-hierarchy-vs-root-logger
+
+# http://stackoverflow.com/a/24956305/1076493
+# filter messages lower than level (exclusive)
+class lf_local_log_method:
+    def __init__(self):
+        # test the local logging
+        pass
+
+    def log_local(self):
+        logger.debug("A DEBUG message from " + __name__)
+        logger.info("An INFO message from " + __name__)
+        logger.warning("An WARNING message from " + __name__)
+        logger.error("An ERROR message from + " + __name__)
+        logger.critical("An CRITICAL message from + " + __name__)
+
+def main():
+
+    # Configure the logging class to configure the root logger 
+    # properties
+    logger_config = lf_logger_config.lf_logger_config()
+
+    # Example of setting the level to debug for base config
+    logger_config.set_level_debug()
+
+    # example of different time stap
+    # logger_config.set_asctime()
+    logger.info("An INFO message asctime from " + __name__)
+    logger.error("An ERROR message asctime from " + __name__)
+
+    # Example of setting up 
+
+    # Example to read the json config
+    # set the configuration file 
+    logger_config.lf_logger_config_json = "lf_logger_config_example.json"
+    logger_config.load_lf_logger_config()
+
+    logger.info("An INFO message asctime from " + __name__)
+    logger.error("An ERROR message asctime from " + __name__)
+
+    # This design patter is here just for completeness 
+    # please use the json configuration for individual
+    # module sets
+    # example to set level for module - try to use the json
+    # logging.getLogger('sublog').setLevel(logging.ERROR)
+    # set level for lower level module
+    # logging.getLogger('sublog2').setLevel(logging.ERROR)
+    # bogus logger.
+
+    # Example does not fail if logger not present
+    logging.getLogger('sublog3_pepper').setLevel(logging.ERROR)
+    
+    lf_sublogger.sublogger()
+
+    # check local logging
+    lf_local_log = lf_local_log_method()
+    lf_local_log.log_local()
+
+    # check printing to stderr is caught
+    print("stderr - Test", file=sys.stderr)
+
+    sys.exit(1)
+
+if __name__ == '__main__':
+    main()
+

py-scripts/sandbox/lf_sublogger.py

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+#!/usr/bin/env python3
+
+import sys
+import os
+import logging
+import importlib
+
+sys.path.append(os.path.join(os.path.abspath(__file__ + "../../../../")))
+lf_sublogger_2 = importlib.import_module("py-scripts.sandbox.lf_sublogger_2")
+
+
+logger = logging.getLogger(__name__)
+
+
+def sublogger():
+    logger.debug("A DEBUG message from " + __name__)
+    logger.info("An INFO message from " + __name__)
+    logger.warning("An WARNING message from " + __name__)
+    logger.error("An ERROR message from + " + __name__)
+    logger.critical("An CRITICAL message from + " + __name__)
+    lf_sublogger_2.sublogger()
+    logger.error("An ERROR message from + " + __name__)
+    lf_sublogger_2.sublogger_2a()

py-scripts/sandbox/lf_sublogger_2.py

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+#!/usr/bin/env python3
+import sys
+import logging
+import importlib
+
+logger = logging.getLogger(__name__)
+
+def sublogger():
+    logger.debug("A DEBUG message from " + __name__)
+    logger.info("An INFO message from " + __name__)
+    logger.warning("An WARNING message from " + __name__)
+    logger.error("An ERROR message from + " + __name__)
+    logger.critical("An CRITICAL message from + " + __name__)
+
+
+def sublogger_2a():
+    logger.debug("A DEBUG message from " + __name__)
+    logger.info("An INFO message from " + __name__)
+    logger.warning("An WARNING message from " + __name__)
+    logger.error("An ERROR message from + " + __name__)
+    logger.critical("An CRITICAL message from + " + __name__)