7. Module three logging module

1. Logging module

# Python's logging module provides a standard log interface through which you can store logs in various formats, logging logs can be divided into # Debug (), info (), warning (), error () and critical () 5 levels # Level when it's used# DEBUG detailed information, typically of interest when diagnosing problem s.# INFO Confirmation that things is working as expected.# WARNING an indication that something Unex Pected happened, or indicative of some problem in the near future (e.g "Disk space low").  The software is still working as expected.# ERROR Due to a more serious problem, the software have not been able  To perform some function.# CRITICAL A serious error, indicating this program itself could be unable to continue Running. Different log levels correspond to different values, as follows: CRITICAL = 50FATAL = Criticalerror = 40WARNING = 30WARN = Warninginfo = 20DEBUG = 10 Format: Loggi Ng. Formatter ('% (asctime) s-% (name) s-% (levelname) s-% (message) s ')% (name) s name of the logger (logging channel)% (Levelno) s Numeric logging level for the message (Debug, INFO, WARNING, ERROR, CRITICAL)% (levelname) s Text logging level for the message ("Debug"  , "INFO", "WARNING", "ERROR", "CRITICAL")% (pathname) s full pathname of the source file where the          Logging call was issued (if available)% (filename) s filename portion of pathname% (module) s                    Module (name portion of filename)% (Lineno) d Source Line number where the logging call was issued                     (if available)% (FuncName) s Function name% (created) f time when the LogRecord is created (Time.time () return value)% (asctime) s textual time when the LogRecord is created% (msecs) d Millis                    Econd portion of the creation time% (relativecreated) d time in milliseconds when the LogRecord is created, Relative to the time the logging module is loaded (typically at application startup time)% (thread) D Thread ID (if Available)% (ThreadName) s Thread name (if available)% (process) d process ID (if available)% (message) s The result of Record.getmessage (), computed just as the record is emitted

Print Log to screen:

# #日志打印到屏幕logging. Warning ("User [Alex] attempted wrong password more than 3 times") logging.critical ("Server was down")

Log output to file:

Logging.basicconfig (filename= ' Python.log ', level=logging.info,format= '% (asctime) s% (message) s ', datefmt= '%m/%d/%y %i:%m:%s%p ') logging.debug (' This message should go to the log file ') Logging.info (' so should this ') logging.warning (' and th is, too ')

Screen log bidirectional output:

#如果需要日志和屏幕同时输出的话, the following action is required # The logging library takes a modular approach and offers several categories of Components:logger s, handlers, filters, and formatters.# loggers expose the interface that application code directly uses.# handlers send th e log records (created by loggers) to the appropriate destination.# Filters provide a finer grained facility for Determini ng which log records to output.# formatters Specify the layout of log records in the final output.# 1, create a log object Logger=logg Ing.getlogger (' Test_log ') logger.setlevel (logging. DEBUG) # 2, create the console handler and set the rank ch = logging. Streamhandler () Ch.setlevel (logging. WARNING) fh = logging. Filehandler () Fh.setlevel (logging. DEBUG) # 3, create log format formatter = logging. Formatter ('% (asctime) s-% (name) s-% (levelname) s-% (message) s ') Ch.setformatter (Formatter) fh.setformatter (Formatter # 4, add log instance to Handlerlogger.addhandler (CH) logger.addhandler (FH) # 5, Print log test import logging#create Loggerlogger = Logging.getlogger (' Test-log ') logger.setlevel (logging. DEBUG) # Create Console handler and set level to DEBUGCH = logging. Streamhandler () Ch.setlevel (logging. ERROR) # Create file handler and set level to WARNINGFH = logging. Filehandler ("Python.log") fh.setlevel (logging. WARNING) # Create Formatterformatter = logging. Formatter ('% (asctime) s-% (name) s-% (levelname) s-% (message) s ') # Add Formatter to CH and fhch.setformatter (Formatter) FH. Setformatter (Formatter) # Add ch and fh to Loggerlogger.addhandler (CH) logger.addhandler (FH) # ' application ' Codelogger.debug (' Debug Message ') Logger.info (' info message ') Logger.warn (' Warn message ') logger.error (' Error message ') logger.critical (' Critical message ')

　　

7. Module three logging module