Transfer: https://www.cnblogs.com/jsondai/p/9663633.html
First, the log level
debug (debug information) info () warning (warnings) error (error message) critical (fatal information) from left to right is getting worse
| Log level (level) | description |
|---|---|
| DEBUG | The most detailed log information, the typical scenario is a problem diagnosis |
| INFO | Second only to the level of detail DEBUG, usually only record key node information to confirm everything is as we expected to work |
| WARNING | Information when some undesirable things happen records (such as low disk space), but this time an application or normal operation |
| ERROR | Because of a more serious problem leading to record certain functions can not work properly when the information |
| CRITICAL | In the event of a serious error, leading to the recorded information can not continue to run the application |
Note that the system only displays warning (warnings) above the level of logging, such as we enter the code below:
import logging logging.debug ( 'This is a level debug information') # output is filtered out logging.info ( 'This is a level information info') # output is filtered out logging.warning ( 'This is a warning level information') logging.error ( 'This is a level error information') logging.critical ( 'This is a critical level information')
Console output
5 lines of code written data, the actual console only three lines, it is because the system default output warning (warning) and above the log.
If you need to show all, you need to call
logging.basicConfig (level = logging.DEBUG) #basicConfig basic configuration can enter a keyword parameters, level is meant logging.DEBUG grade level must be capitalized if it is the calling function needs to lowercase
In the level where the display specified level. Plus run after logging.basicConfig, the following results can show all out
Second, the log output format
The log output to the console or file
fp = logging.FileHandler ( 'a.txt', encoding = 'utf-8') # log records to a file fs = logging.StreamHandler () # log to the console.
On the call handler
import logging
LOG_FORMAT = "% (asctime) s -% (levelname) s -% (message) s" # formatted output log
DATE_FORMAT = "% m /% d /% Y% H:% M:% S% p" # Date Format
fp = logging.FileHandler('a.txt', encoding='utf-8')
fs = logging.StreamHandler()
logging.basicConfig(level=logging.DEBUG, format=LOG_FORMAT, datefmt=DATE_FORMAT, handlers=[fp, fs]) # 调用
logging.debug("This is a debug log.哈哈")
logging.info("This is a info log.")
logging.warning("This is a warning log.")
logging.error("This is a error log.")
logging.critical("This is a critical log.")
Console and log files to be able to show the