如何使用日志记录Python模块写入文件?

时间:2011-06-17 13:44:22

标签: python logging

如何使用Python中的logging模块写入文件?每当我尝试使用它时,它就会打印出消息。

10 个答案:

答案 0 :(得分:114)

使用logging.basicConfig而不是logging.fileHandler()

的示例
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')

按顺序,这五个部分执行以下操作:

  1. 设置输出文件(filename=logname
  2. 将其设置为追加而不是覆盖(filemode='a'
  3. 确定输出消息的格式(format=...
  4. 确定输出时间的格式(datefmt='%H:%M:%S'
  5. 并确定它将接受的最低消息级别(level=logging.DEBUG)。

答案 1 :(得分:46)

取自“logging cookbook”:

# 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)

你很高兴。

P.S。请务必阅读logging HOWTO

答案 2 :(得分:10)

我更喜欢使用配置文件。当我从开发到发布时,它允许我在不更改代码的情况下切换日志记录级别,位置等。我只是打包一个具有相同名称的不同配置文件,并使用相同的定义记录器。

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()

这是我的日志配置文件的代码

#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

答案 3 :(得分:9)

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

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

答案 4 :(得分:5)

这是一种更简单的解决方法。此解决方案不使用 配置字典,并使用旋转文件处理程序,如下所示:

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')

或者像这样:

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')

handlers变量需要是可迭代的。 logpath + filename和debug_level只是保存 各自的信息。当然,函数参数的值是向上的 给你。

我第一次使用日志记录模块时,我写了以下错误,导致生成OS文件锁定错误( 以上是解决方法):

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))

鲍勃是你的叔叔!

答案 5 :(得分:4)

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

  

位于核心FileHandler包中的logging类将日志记录输出发送到磁盘文件。

答案 6 :(得分:0)

import sys
import logging

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

答案 7 :(得分:0)

  

此示例应该可以正常工作。我为控制台添加了流处理程序。安慰   日志和文件处理程序数据应该相似。

    # 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, 

答案 8 :(得分:0)

格式说明

#%(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. 

正常的通话方式

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')

输出

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

使用Dict,调用值

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

输出

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!

答案 9 :(得分:0)

这是两个示例,一个示例打印日志(stdout),另一个示例将日志写入文件:

import logging
import sys

logger = logging.getLogger()
logger.setLevel(logging.INFO)
formatter = logging.Formatter('%(asctime)s | %(levelname)s | %(message)s')

stdout_handler = logging.StreamHandler(sys.stdout)
stdout_handler.setLevel(logging.DEBUG)
stdout_handler.setFormatter(formatter)

file_handler = logging.FileHandler('logs.log')
file_handler.setLevel(logging.DEBUG)
file_handler.setFormatter(formatter)


logger.addHandler(file_handler)
logger.addHandler(stdout_handler)

在此示例中,将打印所有日志,并将它们写入名为logs.log的文件