#!/usr/bin/env python import logging import logging.handlers ''' Log both to a file and to console: use 2 different handlers Logging: http://docs.python.org/2/library/logging.html Formatter: http://docs.python.org/2/library/logging.html#logrecord-attributes ''' def create_logger(logger_name, log_level=logging.WARNING, filename=None, format_str=None): ''' Create a logger that log to the console, if a filename is supplied, log to that file as well. ''' logger = logging.getLogger(logger_name) logger.setLevel(log_level) # create console handler and set appropriate level ch = logging.StreamHandler() ch.setLevel(log_level) formatter = logging.Formatter(format_str or "%(asctime)s %(name)s %(levelname)-8s %(message)s") ch.setFormatter(formatter) logger.addHandler(ch) # Create a file handler and set appropriate level if filename: fh = logging.FileHandler(filename=filename, mode='w') fh.setLevel(log_level) fformatter = logging.Formatter( '%(asctime)s;%(filename)s;%(lineno)d;%(levelname)s;%(message)s', "%Y-%m-%d %H:%M:%S") fh.setFormatter(fformatter) logger.addHandler(fh) return logger def main(): log_filename = 'out.log' logger = create_logger('demo', logging.DEBUG, log_filename) logger.debug("debug message") logger.info("info message") logger.warning("warn message") logger.error("error message") logger.critical("critical message") # Show the log file contents print('---') print(log_filename) print('---') with open(log_filename) as f: print(f.read()) if __name__ == '__main__': main()