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This article is about how to learn Pathon log ogging module, the editor thinks it is very practical, so I share it with you. I hope you can get something after reading this article. Let's take a look at it with the editor.

Log logging module learning of python

Directory (?) [+]

Simply print the log to the screen

Configure the output format and mode of the log through the loggingbasicConfig function

Output the log to both the file and the screen

Logging log rollback

Configure logs through the loggingconfig module

Logging is thread safe

1. Simply print the log to the screen

Import logging

Logging.debug ('This

Is debug message')

Logging.info ('This

Is info message')

Logging.warning ('This

Is warning message')

Print on the screen:

WARNING:root:This is warning message

By default, logging prints the log to the screen, and the log level is WARNING

The log level size relationship is CRITICAL > ERROR > WARNING > INFO > DEBUG > NOTSET. Of course, you can also define the log level yourself.

two。 Configure the output format and mode of the log through the logging.basicConfig function

Import logging

Logging.basicConfig (level=logging.DEBUG

Format='% (asctime) s

% (filename) s [line:% (lineno) d]% (levelname) s% (message) s'

Datefmt='%a

% d% b% Y% HRV% MVA% S'

Filename='myapp.log'

Filemode='w')

Logging.debug ('This

Is debug message')

Logging.info ('This

Is info message')

Logging.warning ('This

Is warning message')

The contents of the. / myapp.log file are:

Sun, 24 May 2009 21:48:54 demo2.py [line:11] DEBUG This is debug message

Sun, 24 May 2009 21:48:54 demo2.py [line:12] INFO This is info message

Sun, 24 May 2009 21:48:54 demo2.py [line:13] WARNING This is warning message

The parameters of the logging.basicConfig function:

Filename: specify the log file name

Filemode: has the same meaning as the file function, specifying the opening mode of the log file,'w' or'a'

Format: specify the format and content of the output. Format can output a lot of useful information, as shown in the example above:

% (levelno) s: print log-level numeric values

% (levelname) s: print log level name

% (pathname) s: print the path of the currently executing program, which is actually sys.argv [0]

% (filename) s: print the name of the currently executing program

% (funcName) s: current function for printing logs

% (lineno) d: print the current line number of the log

% (asctime) s: time the log was printed

% (thread) d: print thread ID

% (threadName) s: print thread name

% (process) d: print process ID

% (message) s: print log information

Datefmt: specify the time format, same as time.strftime ()

Level: sets the log level. Default is logging.WARNING.

Stream: specify the output stream of the log. You can specify the output to sys.stderr,sys.stdout or file. Default output to sys.stderr. When both stream and filename are specified, stream is ignored.

3. Output the log to both the file and the screen

Import logging

Logging.basicConfig (level=logging.DEBUG

Format='% (asctime) s

% (filename) s [line:% (lineno) d]% (levelname) s% (message) s'

Datefmt='%a

% d% b% Y% HRV% MVA% S'

Filename='myapp.log'

Filemode='w')

#

# define a StreamHandler, print log information at INFO level or higher to standard error, and add it to the current log processing object #

Console = logging.StreamHandler ()

Console.setLevel (logging.INFO)

Formatter = logging.Formatter ('% (name)-12s:

% (levelname)-8s% (message) s')

Console.setFormatter (formatter)

Logging.getLogger ('') .addHandler (console)

#

Logging.debug ('This

Is debug message')

Logging.info ('This

Is info message')

Logging.warning ('This

Is warning message')

Print on the screen:

Root: INFO This is info message

Root: WARNING This is warning message

The contents of the. / myapp.log file are:

Sun, 24 May 2009 21:48:54 demo2.py [line:11] DEBUG This is debug message

Sun, 24 May 2009 21:48:54 demo2.py [line:12] INFO This is info message

Sun, 24 May 2009 21:48:54 demo2.py [line:13] WARNING This is warning message

4.logging log rollback

Import logging

From logging.handlers import RotatingFileHandler

#

# define a RotatingFileHandler to back up up to 5 log files, each with a maximum of 10m

Rthandler = RotatingFileHandler ('myapp.log', maxBytes=10*1024*1024,backupCount=5)

Rthandler.setLevel (logging.INFO)

Formatter = logging.Formatter ('% (name)-12s:

% (levelname)-8s% (message) s')

Rthandler.setFormatter (formatter)

Logging.getLogger ('') .addHandler (Rthandler)

#

As you can see from the above example and this example, logging has a master object for log processing, and other processing methods are added through addHandler.

Several handle methods of logging are as follows:

Logging.StreamHandler: log output to a stream, which can be sys.stderr, sys.stdout, or file

Logging.FileHandler: log output to file

Log rollback method, using RotatingFileHandler and TimedRotatingFileHandler in actual use

Logging.handlers.BaseRotatingHandler

Logging.handlers.RotatingFileHandler

Logging.handlers.TimedRotatingFileHandler

Logging.handlers.SocketHandler: remote output log to TCP/IP sockets

Logging.handlers.DatagramHandler: remote output log to UDP sockets

Logging.handlers.SMTPHandler: remote output log to email address

Logging.handlers.SysLogHandler: log output to syslog

Logging.handlers.NTEventLogHandler: remote output log to Windows NT/2000/XP event log

Logging.handlers.MemoryHandler: defined buffer for log output to memory

Logging.handlers.HTTPHandler: remote output to the HTTP server via "GET" or "POST"

Because StreamHandler and FileHandler are commonly used log processing methods, they are directly included in the logging module, while other methods are included in the logging.handlers module.

For the use of the other processing methods mentioned above, see the python2.5 manual!

5. Configure logs through the logging.config module

# logger.conf

# # #

[loggers]

Keys=root,example01,example02

[logger_root]

Level=DEBUG

Handlers=hand01,hand02

[logger_example01]

Handlers=hand01,hand02

Qualname=example01

Propagate=0

[logger_example02]

Handlers=hand01,hand03

Qualname=example02

Propagate=0

# # #

[handlers]

Keys=hand01,hand02,hand03

[handler_hand01]

Class=StreamHandler

Level=INFO

Formatter=form02

Args= (sys.stderr,)

[handler_hand02]

Class=FileHandler

Level=DEBUG

Formatter=form01

Args= ('myapp.log', 'a')

[handler_hand03]

Class=handlers.RotatingFileHandler

Level=INFO

Formatter=form02

Args= ('myapp.log',' asides, 10 '1024' 1024, 5)

# # #

[formatters]

Keys=form01,form02

[formatter_form01]

Format=% (asctime) s% (filename) s [line:% (lineno) d]% (levelname) s% (message) s

Datefmt=%a, d b Y H:%M:%S

[formatter_form02]

Format=% (name)-12s:% (levelname)-8s% (message) s

Datefmt=

Example 3 above:

Import logging

Import logging.config

Logging.config.fileConfig ("logger.conf")

Logger = logging.getLogger ("example01")

Logger.debug ('This

Is debug message')

Logger.info ('This

Is info message')

Logger.warning ('This

Is warning message')

Example 4 above:

Import logging

Import logging.config

Logging.config.fileConfig ("logger.conf")

Logger = logging.getLogger ("example02")

Logger.debug ('This

Is debug message')

Logger.info ('This

Is info message')

Logger.warning ('This

Is warning message')

6.logging is thread-safe, which is how to learn the Pathon log ogging module. The editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

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