Package: python-json-logger
OverviewThis library is provided to allow standard python logging to output log data as json objects. With JSON we can make our logs more readable by machines and we can stop writing custom parsers for syslog type records.NewsHi, I see this package is quiet alive and I am sorry for ignoring it so long. I will be stepping up my maintenance of this package so please allow me a week to get things back in order (and most likely a new minor version) and I'll post and update here once I am caught up.InstallingPip:pip install python-json-loggerPypi:https://pypi.python.org/pypi/python-json-loggerManual:python setup.py installUsageIntegrating with Python's logging frameworkJson outputs are provided by the JsonFormatter logging formatter. You can add the custom formatter like below:Please note: version 0.1.0 has changed the import structure, please update to the following example for proper importingimportloggingfrompythonjsonloggerimportjsonloggerlogger=logging.getLogger()logHandler=logging.StreamHandler()formatter=jsonlogger.JsonFormatter()logHandler.setFormatter(formatter)logger.addHandler(logHandler)Customizing fieldsThe fmt parser can also be overidden if you want to have required fields that differ from the default of justmessage.These two invocations are equivalent:classCustomJsonFormatter(jsonlogger.JsonFormatter):defparse(self):returnself._fmt.split(';')formatter=CustomJsonFormatter('one;two')# is equivalent to:formatter=jsonlogger.JsonFormatter('%(one)s%(two)s')You can also add extra fields to your json output by specifying a dict in place of message, as well as by specifying anextra={}argument.Contents of these dictionaries will be added at the root level of the entry and may override basic fields.You can also use theadd_fieldsmethod to add to or generally normalize the set of default set of fields, it is called for every log event. For example, to unify default fields with those provided bystructlogyou could do something like this:classCustomJsonFormatter(jsonlogger.JsonFormatter):defadd_fields(self,log_record,record,message_dict):super(CustomJsonFormatter,self).add_fields(log_record,record,message_dict)ifnotlog_record.get('timestamp'):# this doesn't use record.created, so it is slightly offnow=datetime.utcnow().strftime('%Y-%m-%dT%H:%M:%S.%fZ')log_record['timestamp']=nowiflog_record.get('level'):log_record['level']=log_record['level'].upper()else:log_record['level']=record.levelnameformatter=CustomJsonFormatter('%(timestamp)s%(level)s%(name)s%(message)s')Items added to the log record will be included ineverylog message, no matter what the format requires.Adding custom object serializationFor custom handling of object serialization you can specify default json object translator or provide a custom encoderdefjson_translate(obj):ifisinstance(obj,MyClass):return{"special":obj.special}formatter=jsonlogger.JsonFormatter(json_default=json_translate,json_encoder=json.JSONEncoder)logHandler.setFormatter(formatter)logger.info({"special":"value","run":12})logger.info("classic message",extra={"special":"value","run":12})Using a Config FileTo use the module with a config file using thefileConfigfunction, use the classpythonjsonlogger.jsonlogger.JsonFormatter. Here is a sample config file.[loggers]keys=root,custom[logger_root]handlers=[logger_custom]level=INFOhandlers=customqualname=custom[handlers]keys=custom[handler_custom]class=StreamHandlerlevel=INFOformatter=jsonargs=(sys.stdout,)[formatters]keys=json[formatter_json]format=%(message)sclass=pythonjsonlogger.jsonlogger.JsonFormatterExample OutputSample JSON with a full formatter (basically the log message from the unit test). Every log message will appear on 1 line like a typical logger.{"threadName":"MainThread","name":"root","thread":140735202359648,"created":1336281068.506248,"process":41937,"processName":"MainProcess","relativeCreated":9.100914001464844,"module":"tests","funcName":"testFormatKeys","levelno":20,"msecs":506.24799728393555,"pathname":"tests/tests.py","lineno":60,"asctime":["12-05-05 22:11:08,506248"],"message":"testing logging format","filename":"tests.py","levelname":"INFO","special":"value","run":12}External ExamplesWesley Tanaka - Structured log files in Python using python-json-loggerArchive