Comment écrire dans un fichier, en utilisant le module Python de journalisation?

Comment puis-je utiliser le module de journalisation en Python pour écrire dans un fichier? Chaque fois que j'essaie de l'utiliser, il imprime simplement le message.

Un exemple d'utilisation logging.basicConfigplutôt quelogging.fileHandler()

logging.basicConfig(filename=logname,
                            filemode='a',
                            format='%(asctime)s,%(msecs)d %(name)s %(levelname)s %(message)s',
                            datefmt='%H:%M:%S',
                            level=logging.DEBUG)

logging.info("Running Urban Planning")

self.logger = logging.getLogger('urbanGUI')

Dans l'ordre, les cinq parties font ce qui suit:

1. définir le fichier de sortie ( filename=logname)
2. définissez-le pour ajouter plutôt que remplacer ( filemode='a')
3. déterminer le format du message de sortie (format=... )
4. déterminer le format de l'heure de sortie ( datefmt='%H:%M:%S')
5. et déterminez le niveau de message minimum qu'il acceptera ( level=logging.DEBUG).

Tiré du " livre de recettes de journalisation ":

# create logger with 'spam_application'
logger = logging.getLogger('spam_application')
logger.setLevel(logging.DEBUG)
# create file handler which logs even debug messages
fh = logging.FileHandler('spam.log')
fh.setLevel(logging.DEBUG)
logger.addHandler(fh)

Et vous êtes prêt à partir.

PS Assurez-vous de lire également le HOWTO de journalisation .

Je préfère utiliser un fichier de configuration. Cela me permet de changer les niveaux de journalisation, les emplacements, etc. sans changer de code lorsque je passe du développement à la publication. J'emballe simplement un fichier de configuration différent avec le même nom et avec les mêmes enregistreurs définis.

import logging.config
if __name__ == '__main__':
    # Configure the logger
    # loggerConfigFileName: The name and path of your configuration file
    logging.config.fileConfig(path.normpath(loggerConfigFileName))

    # Create the logger
    # Admin_Client: The name of a logger defined in the config file
    mylogger = logging.getLogger('Admin_Client')

    msg='Bite Me'
    myLogger.debug(msg)
    myLogger.info(msg)
    myLogger.warn(msg)
    myLogger.error(msg)
    myLogger.critical(msg)

    # Shut down the logger
    logging.shutdown()

Voici mon code pour le fichier de configuration du journal

#These are the loggers that are available from the code
#Each logger requires a handler, but can have more than one
[loggers]
keys=root,Admin_Client


#Each handler requires a single formatter
[handlers]
keys=fileHandler, consoleHandler


[formatters]
keys=logFormatter, consoleFormatter


[logger_root]
level=DEBUG
handlers=fileHandler


[logger_Admin_Client]
level=DEBUG
handlers=fileHandler, consoleHandler
qualname=Admin_Client
#propagate=0 Does not pass messages to ancestor loggers(root)
propagate=0


# Do not use a console logger when running scripts from a bat file without a console
# because it hangs!
[handler_consoleHandler]
class=StreamHandler
level=DEBUG
formatter=consoleFormatter
args=(sys.stdout,)# The comma is correct, because the parser is looking for args


[handler_fileHandler]
class=FileHandler
level=DEBUG
formatter=logFormatter
# This causes a new file to be created for each script
# Change time.strftime("%Y%m%d%H%M%S") to time.strftime("%Y%m%d")
# And only one log per day will be created. All messages will be amended to it.
args=("D:\\Logs\\PyLogs\\" + time.strftime("%Y%m%d%H%M%S")+'.log', 'a')


[formatter_logFormatter]
#name is the name of the logger root or Admin_Client
#levelname is the log message level debug, warn, ect 
#lineno is the line number from where the call to log is made
#04d is simple formatting to ensure there are four numeric places with leading zeros
#4s would work as well, but would simply pad the string with leading spaces, right justify
#-4s would work as well, but would simply pad the string with trailing spaces, left justify
#filename is the file name from where the call to log is made
#funcName is the method name from where the call to log is made
#format=%(asctime)s | %(lineno)d | %(message)s
#format=%(asctime)s | %(name)s | %(levelname)s | %(message)s
#format=%(asctime)s | %(name)s | %(module)s-%(lineno) | %(levelname)s | %(message)s
#format=%(asctime)s | %(name)s | %(module)s-%(lineno)04d | %(levelname)s | %(message)s
#format=%(asctime)s | %(name)s | %(module)s-%(lineno)4s | %(levelname)-8s | %(message)s

format=%(asctime)s | %(levelname)-8s | %(lineno)04d | %(message)s


#Use a separate formatter for the console if you want
[formatter_consoleFormatter]
format=%(asctime)s | %(levelname)-8s | %(filename)s-%(funcName)s-%(lineno)04d | %(message)s

http://docs.python.org/library/logging.html#logging.basicConfig

logging.basicConfig(filename='/path/to/your/log', level=....)

voici une façon plus simple de procéder. cette solution n'utilise pas de dictionnaire de configuration et utilise un gestionnaire de fichier de rotation, comme ceci:

import logging
from logging.handlers import RotatingFileHandler

logging.basicConfig(handlers=[RotatingFileHandler(filename=logpath+filename,
                     mode='w', maxBytes=512000, backupCount=4)], level=debug_level,
                     format='%(levelname)s %(asctime)s %(message)s', 
                    datefmt='%m/%d/%Y%I:%M:%S %p')

logger = logging.getLogger('my_logger')

ou comme ça:

import logging
from logging.handlers import RotatingFileHandler

handlers = [
            RotatingFileHandler(filename=logpath+filename, mode='w', maxBytes=512000, 
                                backupCount=4)
           ]
logging.basicConfig(handlers=handlers, level=debug_level, 
                    format='%(levelname)s %(asctime)s %(message)s', 
                    datefmt='%m/%d/%Y%I:%M:%S %p')

logger = logging.getLogger('my_logger')

la variable handlers doit être une variable itérable. logpath + filename et debug_level ne sont que des variables contenant les informations respectives. bien sûr, les valeurs des paramètres de fonction dépendent de vous.

la première fois que j'utilisais le module de journalisation, j'ai commis l'erreur d'écrire ce qui suit, ce qui génère une erreur de verrouillage de fichier du système d'exploitation (ce qui précède est la solution à cela):

import logging
from logging.handlers import RotatingFileHandler

logging.basicConfig(filename=logpath+filename, level=debug_level, format='%(levelname)s %(asctime)s %(message)s', datefmt='%m/%d/%Y
 %I:%M:%S %p')

logger = logging.getLogger('my_logger')
logger.addHandler(RotatingFileHandler(filename=logpath+filename, mode='w', 
                  maxBytes=512000, backupCount=4))

et Bob est ton oncle!

http://docs.python.org/library/logging.handlers.html#filehandler

La FileHandlerclasse, située dans le loggingpackage principal , envoie la sortie de journalisation vers un fichier disque.

import sys
import logging

from util import reducer_logfile
logging.basicConfig(filename=reducer_logfile, format='%(message)s',
                    level=logging.INFO, filemode='w')

Cet exemple devrait fonctionner correctement. J'ai ajouté streamhandler pour la console. Les données du journal de la console et du gestionnaire de fichiers doivent être similaires.

    # MUTHUKUMAR_TIME_DATE.py #>>>>>>>> file name(module)

    import sys
    import logging
    import logging.config
    # ================== Logger ================================
    def Logger(file_name):
        formatter = logging.Formatter(fmt='%(asctime)s %(module)s,line: %(lineno)d %(levelname)8s | %(message)s',
                                      datefmt='%Y/%m/%d %H:%M:%S') # %I:%M:%S %p AM|PM format
        logging.basicConfig(filename = '%s.log' %(file_name),format= '%(asctime)s %(module)s,line: %(lineno)d %(levelname)8s | %(message)s',
                                      datefmt='%Y/%m/%d %H:%M:%S', filemode = 'w', level = logging.INFO)
        log_obj = logging.getLogger()
        log_obj.setLevel(logging.DEBUG)
        # log_obj = logging.getLogger().addHandler(logging.StreamHandler())

        # console printer
        screen_handler = logging.StreamHandler(stream=sys.stdout) #stream=sys.stdout is similar to normal print
        screen_handler.setFormatter(formatter)
        logging.getLogger().addHandler(screen_handler)

        log_obj.info("Logger object created successfully..")
        return log_obj
    # =======================================================


MUTHUKUMAR_LOGGING_CHECK.py #>>>>>>>>>>> file name
# calling **Logger** function
file_name = 'muthu'
log_obj =Logger(file_name)
log_obj.info("yes   hfghghg ghgfh".format())
log_obj.critical("CRIC".format())
log_obj.error("ERR".format())
log_obj.warning("WARN".format())
log_obj.debug("debug".format())
log_obj.info("qwerty".format())
log_obj.info("asdfghjkl".format())
log_obj.info("zxcvbnm".format())
# closing file
log_obj.handlers.clear()

OUTPUT:
2019/07/13 23:54:40 MUTHUKUMAR_TIME_DATE,line: 17     INFO | Logger object created successfully..
2019/07/13 23:54:40 MUTHUKUMAR_LOGGING_CHECK,line: 8     INFO | yes   hfghghg ghgfh
2019/07/13 23:54:40 MUTHUKUMAR_LOGGING_CHECK,line: 9 CRITICAL | CRIC
2019/07/13 23:54:40 MUTHUKUMAR_LOGGING_CHECK,line: 10    ERROR | ERR
2019/07/13 23:54:40 MUTHUKUMAR_LOGGING_CHECK,line: 11  WARNING | WARN
2019/07/13 23:54:40 MUTHUKUMAR_LOGGING_CHECK,line: 12    DEBUG | debug
2019/07/13 23:54:40 MUTHUKUMAR_LOGGING_CHECK,line: 13     INFO | qwerty
2019/07/13 23:54:40 MUTHUKUMAR_LOGGING_CHECK,line: 14     INFO | asdfghjkl
2019/07/13 23:54:40 MUTHUKUMAR_LOGGING_CHECK,line: 15     INFO | zxcvbnm

Thanks, 

Description du format

#%(name)s       Name of the logger (logging channel).
#%(levelname)s  Text logging level for the message ('DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL').
#%(asctime)s    Human-readable time when the LogRecord was created. By default this is of the form ``2003-07-08 16:49:45,896'' (the numbers after the comma are millisecond portion of the time).
#%(message)s    The logged message. 

Appel normal

import logging
#logging.basicConfig(level=logging.INFO)
logging.basicConfig(level=logging.DEBUG)
logger = logging.getLogger(__name__)
logger.info('Start reading database')
# read database here
records = {'john': 55, 'tom': 66}
logger.debug('Records: %s', records)
logger.info('Updating records ...')
# update records here
logger.info('Finish updating records')

Production

INFO:__main__:Start reading database
DEBUG:__main__:Records: {'john': 55, 'tom': 66}
INFO:__main__:Updating records ...
INFO:__main__:Finish updating records

Utilisation de Dict, Call values

import logging
import logging.config
import otherMod2

def main():
    """
    Based on http://docs.python.org/howto/logging.html#configuring-logging
    """
    dictLogConfig = {
        "version":1,
        "handlers":{
                    "fileHandler":{
                        "class":"logging.FileHandler",
                        "formatter":"myFormatter",
                        "filename":"config2.log"
                        }
                    },        
        "loggers":{
            "exampleApp":{
                "handlers":["fileHandler"],
                "level":"INFO",
                }
            },

        "formatters":{
            "myFormatter":{
                "format":"%(asctime)s - %(name)s - %(levelname)s - %(message)s"
                }
            }
        }

    logging.config.dictConfig(dictLogConfig)

    logger = logging.getLogger("exampleApp")

    logger.info("Program started")
    result = otherMod2.add(7, 8)
    logger.info("Done!")

if __name__ == "__main__":
    main()

otherMod2.py

import logging
def add(x, y):
    """"""
    logger = logging.getLogger("exampleApp.otherMod2.add")
    logger.info("added %s and %s to get %s" % (x, y, x+y))
    return x+y

Production

2019-08-12 18:03:50,026 - exampleApp - INFO - Program started
2019-08-12 18:03:50,026 - exampleApp.otherMod2.add - INFO - added 7 and 8 to get 15
2019-08-12 18:03:50,027 - exampleApp - INFO - Done!